Type.h revision 651f13cea278ec967336033dd032faef0e9fc2ec
1//===--- Type.h - C Language Family Type Representation ---------*- C++ -*-===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10//  This file defines the Type interface and subclasses.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_CLANG_AST_TYPE_H
15#define LLVM_CLANG_AST_TYPE_H
16
17#include "clang/AST/NestedNameSpecifier.h"
18#include "clang/AST/TemplateName.h"
19#include "clang/Basic/Diagnostic.h"
20#include "clang/Basic/ExceptionSpecificationType.h"
21#include "clang/Basic/IdentifierTable.h"
22#include "clang/Basic/LLVM.h"
23#include "clang/Basic/Linkage.h"
24#include "clang/Basic/PartialDiagnostic.h"
25#include "clang/Basic/Specifiers.h"
26#include "clang/Basic/Visibility.h"
27#include "llvm/ADT/APSInt.h"
28#include "llvm/ADT/FoldingSet.h"
29#include "llvm/ADT/iterator_range.h"
30#include "llvm/ADT/Optional.h"
31#include "llvm/ADT/PointerIntPair.h"
32#include "llvm/ADT/PointerUnion.h"
33#include "llvm/ADT/Twine.h"
34#include "llvm/Support/ErrorHandling.h"
35
36namespace clang {
37  enum {
38    TypeAlignmentInBits = 4,
39    TypeAlignment = 1 << TypeAlignmentInBits
40  };
41  class Type;
42  class ExtQuals;
43  class QualType;
44}
45
46namespace llvm {
47  template <typename T>
48  class PointerLikeTypeTraits;
49  template<>
50  class PointerLikeTypeTraits< ::clang::Type*> {
51  public:
52    static inline void *getAsVoidPointer(::clang::Type *P) { return P; }
53    static inline ::clang::Type *getFromVoidPointer(void *P) {
54      return static_cast< ::clang::Type*>(P);
55    }
56    enum { NumLowBitsAvailable = clang::TypeAlignmentInBits };
57  };
58  template<>
59  class PointerLikeTypeTraits< ::clang::ExtQuals*> {
60  public:
61    static inline void *getAsVoidPointer(::clang::ExtQuals *P) { return P; }
62    static inline ::clang::ExtQuals *getFromVoidPointer(void *P) {
63      return static_cast< ::clang::ExtQuals*>(P);
64    }
65    enum { NumLowBitsAvailable = clang::TypeAlignmentInBits };
66  };
67
68  template <>
69  struct isPodLike<clang::QualType> { static const bool value = true; };
70}
71
72namespace clang {
73  class ASTContext;
74  class TypedefNameDecl;
75  class TemplateDecl;
76  class TemplateTypeParmDecl;
77  class NonTypeTemplateParmDecl;
78  class TemplateTemplateParmDecl;
79  class TagDecl;
80  class RecordDecl;
81  class CXXRecordDecl;
82  class EnumDecl;
83  class FieldDecl;
84  class FunctionDecl;
85  class ObjCInterfaceDecl;
86  class ObjCProtocolDecl;
87  class ObjCMethodDecl;
88  class UnresolvedUsingTypenameDecl;
89  class Expr;
90  class Stmt;
91  class SourceLocation;
92  class StmtIteratorBase;
93  class TemplateArgument;
94  class TemplateArgumentLoc;
95  class TemplateArgumentListInfo;
96  class ElaboratedType;
97  class ExtQuals;
98  class ExtQualsTypeCommonBase;
99  struct PrintingPolicy;
100
101  template <typename> class CanQual;
102  typedef CanQual<Type> CanQualType;
103
104  // Provide forward declarations for all of the *Type classes
105#define TYPE(Class, Base) class Class##Type;
106#include "clang/AST/TypeNodes.def"
107
108/// Qualifiers - The collection of all-type qualifiers we support.
109/// Clang supports five independent qualifiers:
110/// * C99: const, volatile, and restrict
111/// * Embedded C (TR18037): address spaces
112/// * Objective C: the GC attributes (none, weak, or strong)
113class Qualifiers {
114public:
115  enum TQ { // NOTE: These flags must be kept in sync with DeclSpec::TQ.
116    Const    = 0x1,
117    Restrict = 0x2,
118    Volatile = 0x4,
119    CVRMask = Const | Volatile | Restrict
120  };
121
122  enum GC {
123    GCNone = 0,
124    Weak,
125    Strong
126  };
127
128  enum ObjCLifetime {
129    /// There is no lifetime qualification on this type.
130    OCL_None,
131
132    /// This object can be modified without requiring retains or
133    /// releases.
134    OCL_ExplicitNone,
135
136    /// Assigning into this object requires the old value to be
137    /// released and the new value to be retained.  The timing of the
138    /// release of the old value is inexact: it may be moved to
139    /// immediately after the last known point where the value is
140    /// live.
141    OCL_Strong,
142
143    /// Reading or writing from this object requires a barrier call.
144    OCL_Weak,
145
146    /// Assigning into this object requires a lifetime extension.
147    OCL_Autoreleasing
148  };
149
150  enum {
151    /// The maximum supported address space number.
152    /// 24 bits should be enough for anyone.
153    MaxAddressSpace = 0xffffffu,
154
155    /// The width of the "fast" qualifier mask.
156    FastWidth = 3,
157
158    /// The fast qualifier mask.
159    FastMask = (1 << FastWidth) - 1
160  };
161
162  Qualifiers() : Mask(0) {}
163
164  /// \brief Returns the common set of qualifiers while removing them from
165  /// the given sets.
166  static Qualifiers removeCommonQualifiers(Qualifiers &L, Qualifiers &R) {
167    // If both are only CVR-qualified, bit operations are sufficient.
168    if (!(L.Mask & ~CVRMask) && !(R.Mask & ~CVRMask)) {
169      Qualifiers Q;
170      Q.Mask = L.Mask & R.Mask;
171      L.Mask &= ~Q.Mask;
172      R.Mask &= ~Q.Mask;
173      return Q;
174    }
175
176    Qualifiers Q;
177    unsigned CommonCRV = L.getCVRQualifiers() & R.getCVRQualifiers();
178    Q.addCVRQualifiers(CommonCRV);
179    L.removeCVRQualifiers(CommonCRV);
180    R.removeCVRQualifiers(CommonCRV);
181
182    if (L.getObjCGCAttr() == R.getObjCGCAttr()) {
183      Q.setObjCGCAttr(L.getObjCGCAttr());
184      L.removeObjCGCAttr();
185      R.removeObjCGCAttr();
186    }
187
188    if (L.getObjCLifetime() == R.getObjCLifetime()) {
189      Q.setObjCLifetime(L.getObjCLifetime());
190      L.removeObjCLifetime();
191      R.removeObjCLifetime();
192    }
193
194    if (L.getAddressSpace() == R.getAddressSpace()) {
195      Q.setAddressSpace(L.getAddressSpace());
196      L.removeAddressSpace();
197      R.removeAddressSpace();
198    }
199    return Q;
200  }
201
202  static Qualifiers fromFastMask(unsigned Mask) {
203    Qualifiers Qs;
204    Qs.addFastQualifiers(Mask);
205    return Qs;
206  }
207
208  static Qualifiers fromCVRMask(unsigned CVR) {
209    Qualifiers Qs;
210    Qs.addCVRQualifiers(CVR);
211    return Qs;
212  }
213
214  // Deserialize qualifiers from an opaque representation.
215  static Qualifiers fromOpaqueValue(unsigned opaque) {
216    Qualifiers Qs;
217    Qs.Mask = opaque;
218    return Qs;
219  }
220
221  // Serialize these qualifiers into an opaque representation.
222  unsigned getAsOpaqueValue() const {
223    return Mask;
224  }
225
226  bool hasConst() const { return Mask & Const; }
227  void setConst(bool flag) {
228    Mask = (Mask & ~Const) | (flag ? Const : 0);
229  }
230  void removeConst() { Mask &= ~Const; }
231  void addConst() { Mask |= Const; }
232
233  bool hasVolatile() const { return Mask & Volatile; }
234  void setVolatile(bool flag) {
235    Mask = (Mask & ~Volatile) | (flag ? Volatile : 0);
236  }
237  void removeVolatile() { Mask &= ~Volatile; }
238  void addVolatile() { Mask |= Volatile; }
239
240  bool hasRestrict() const { return Mask & Restrict; }
241  void setRestrict(bool flag) {
242    Mask = (Mask & ~Restrict) | (flag ? Restrict : 0);
243  }
244  void removeRestrict() { Mask &= ~Restrict; }
245  void addRestrict() { Mask |= Restrict; }
246
247  bool hasCVRQualifiers() const { return getCVRQualifiers(); }
248  unsigned getCVRQualifiers() const { return Mask & CVRMask; }
249  void setCVRQualifiers(unsigned mask) {
250    assert(!(mask & ~CVRMask) && "bitmask contains non-CVR bits");
251    Mask = (Mask & ~CVRMask) | mask;
252  }
253  void removeCVRQualifiers(unsigned mask) {
254    assert(!(mask & ~CVRMask) && "bitmask contains non-CVR bits");
255    Mask &= ~mask;
256  }
257  void removeCVRQualifiers() {
258    removeCVRQualifiers(CVRMask);
259  }
260  void addCVRQualifiers(unsigned mask) {
261    assert(!(mask & ~CVRMask) && "bitmask contains non-CVR bits");
262    Mask |= mask;
263  }
264
265  bool hasObjCGCAttr() const { return Mask & GCAttrMask; }
266  GC getObjCGCAttr() const { return GC((Mask & GCAttrMask) >> GCAttrShift); }
267  void setObjCGCAttr(GC type) {
268    Mask = (Mask & ~GCAttrMask) | (type << GCAttrShift);
269  }
270  void removeObjCGCAttr() { setObjCGCAttr(GCNone); }
271  void addObjCGCAttr(GC type) {
272    assert(type);
273    setObjCGCAttr(type);
274  }
275  Qualifiers withoutObjCGCAttr() const {
276    Qualifiers qs = *this;
277    qs.removeObjCGCAttr();
278    return qs;
279  }
280  Qualifiers withoutObjCLifetime() const {
281    Qualifiers qs = *this;
282    qs.removeObjCLifetime();
283    return qs;
284  }
285
286  bool hasObjCLifetime() const { return Mask & LifetimeMask; }
287  ObjCLifetime getObjCLifetime() const {
288    return ObjCLifetime((Mask & LifetimeMask) >> LifetimeShift);
289  }
290  void setObjCLifetime(ObjCLifetime type) {
291    Mask = (Mask & ~LifetimeMask) | (type << LifetimeShift);
292  }
293  void removeObjCLifetime() { setObjCLifetime(OCL_None); }
294  void addObjCLifetime(ObjCLifetime type) {
295    assert(type);
296    assert(!hasObjCLifetime());
297    Mask |= (type << LifetimeShift);
298  }
299
300  /// True if the lifetime is neither None or ExplicitNone.
301  bool hasNonTrivialObjCLifetime() const {
302    ObjCLifetime lifetime = getObjCLifetime();
303    return (lifetime > OCL_ExplicitNone);
304  }
305
306  /// True if the lifetime is either strong or weak.
307  bool hasStrongOrWeakObjCLifetime() const {
308    ObjCLifetime lifetime = getObjCLifetime();
309    return (lifetime == OCL_Strong || lifetime == OCL_Weak);
310  }
311
312  bool hasAddressSpace() const { return Mask & AddressSpaceMask; }
313  unsigned getAddressSpace() const { return Mask >> AddressSpaceShift; }
314  void setAddressSpace(unsigned space) {
315    assert(space <= MaxAddressSpace);
316    Mask = (Mask & ~AddressSpaceMask)
317         | (((uint32_t) space) << AddressSpaceShift);
318  }
319  void removeAddressSpace() { setAddressSpace(0); }
320  void addAddressSpace(unsigned space) {
321    assert(space);
322    setAddressSpace(space);
323  }
324
325  // Fast qualifiers are those that can be allocated directly
326  // on a QualType object.
327  bool hasFastQualifiers() const { return getFastQualifiers(); }
328  unsigned getFastQualifiers() const { return Mask & FastMask; }
329  void setFastQualifiers(unsigned mask) {
330    assert(!(mask & ~FastMask) && "bitmask contains non-fast qualifier bits");
331    Mask = (Mask & ~FastMask) | mask;
332  }
333  void removeFastQualifiers(unsigned mask) {
334    assert(!(mask & ~FastMask) && "bitmask contains non-fast qualifier bits");
335    Mask &= ~mask;
336  }
337  void removeFastQualifiers() {
338    removeFastQualifiers(FastMask);
339  }
340  void addFastQualifiers(unsigned mask) {
341    assert(!(mask & ~FastMask) && "bitmask contains non-fast qualifier bits");
342    Mask |= mask;
343  }
344
345  /// hasNonFastQualifiers - Return true if the set contains any
346  /// qualifiers which require an ExtQuals node to be allocated.
347  bool hasNonFastQualifiers() const { return Mask & ~FastMask; }
348  Qualifiers getNonFastQualifiers() const {
349    Qualifiers Quals = *this;
350    Quals.setFastQualifiers(0);
351    return Quals;
352  }
353
354  /// hasQualifiers - Return true if the set contains any qualifiers.
355  bool hasQualifiers() const { return Mask; }
356  bool empty() const { return !Mask; }
357
358  /// \brief Add the qualifiers from the given set to this set.
359  void addQualifiers(Qualifiers Q) {
360    // If the other set doesn't have any non-boolean qualifiers, just
361    // bit-or it in.
362    if (!(Q.Mask & ~CVRMask))
363      Mask |= Q.Mask;
364    else {
365      Mask |= (Q.Mask & CVRMask);
366      if (Q.hasAddressSpace())
367        addAddressSpace(Q.getAddressSpace());
368      if (Q.hasObjCGCAttr())
369        addObjCGCAttr(Q.getObjCGCAttr());
370      if (Q.hasObjCLifetime())
371        addObjCLifetime(Q.getObjCLifetime());
372    }
373  }
374
375  /// \brief Remove the qualifiers from the given set from this set.
376  void removeQualifiers(Qualifiers Q) {
377    // If the other set doesn't have any non-boolean qualifiers, just
378    // bit-and the inverse in.
379    if (!(Q.Mask & ~CVRMask))
380      Mask &= ~Q.Mask;
381    else {
382      Mask &= ~(Q.Mask & CVRMask);
383      if (getObjCGCAttr() == Q.getObjCGCAttr())
384        removeObjCGCAttr();
385      if (getObjCLifetime() == Q.getObjCLifetime())
386        removeObjCLifetime();
387      if (getAddressSpace() == Q.getAddressSpace())
388        removeAddressSpace();
389    }
390  }
391
392  /// \brief Add the qualifiers from the given set to this set, given that
393  /// they don't conflict.
394  void addConsistentQualifiers(Qualifiers qs) {
395    assert(getAddressSpace() == qs.getAddressSpace() ||
396           !hasAddressSpace() || !qs.hasAddressSpace());
397    assert(getObjCGCAttr() == qs.getObjCGCAttr() ||
398           !hasObjCGCAttr() || !qs.hasObjCGCAttr());
399    assert(getObjCLifetime() == qs.getObjCLifetime() ||
400           !hasObjCLifetime() || !qs.hasObjCLifetime());
401    Mask |= qs.Mask;
402  }
403
404  /// \brief Determines if these qualifiers compatibly include another set.
405  /// Generally this answers the question of whether an object with the other
406  /// qualifiers can be safely used as an object with these qualifiers.
407  bool compatiblyIncludes(Qualifiers other) const {
408    return
409      // Address spaces must match exactly.
410      getAddressSpace() == other.getAddressSpace() &&
411      // ObjC GC qualifiers can match, be added, or be removed, but can't be
412      // changed.
413      (getObjCGCAttr() == other.getObjCGCAttr() ||
414       !hasObjCGCAttr() || !other.hasObjCGCAttr()) &&
415      // ObjC lifetime qualifiers must match exactly.
416      getObjCLifetime() == other.getObjCLifetime() &&
417      // CVR qualifiers may subset.
418      (((Mask & CVRMask) | (other.Mask & CVRMask)) == (Mask & CVRMask));
419  }
420
421  /// \brief Determines if these qualifiers compatibly include another set of
422  /// qualifiers from the narrow perspective of Objective-C ARC lifetime.
423  ///
424  /// One set of Objective-C lifetime qualifiers compatibly includes the other
425  /// if the lifetime qualifiers match, or if both are non-__weak and the
426  /// including set also contains the 'const' qualifier.
427  bool compatiblyIncludesObjCLifetime(Qualifiers other) const {
428    if (getObjCLifetime() == other.getObjCLifetime())
429      return true;
430
431    if (getObjCLifetime() == OCL_Weak || other.getObjCLifetime() == OCL_Weak)
432      return false;
433
434    return hasConst();
435  }
436
437  /// \brief Determine whether this set of qualifiers is a strict superset of
438  /// another set of qualifiers, not considering qualifier compatibility.
439  bool isStrictSupersetOf(Qualifiers Other) const;
440
441  bool operator==(Qualifiers Other) const { return Mask == Other.Mask; }
442  bool operator!=(Qualifiers Other) const { return Mask != Other.Mask; }
443
444  LLVM_EXPLICIT operator bool() const { return hasQualifiers(); }
445
446  Qualifiers &operator+=(Qualifiers R) {
447    addQualifiers(R);
448    return *this;
449  }
450
451  // Union two qualifier sets.  If an enumerated qualifier appears
452  // in both sets, use the one from the right.
453  friend Qualifiers operator+(Qualifiers L, Qualifiers R) {
454    L += R;
455    return L;
456  }
457
458  Qualifiers &operator-=(Qualifiers R) {
459    removeQualifiers(R);
460    return *this;
461  }
462
463  /// \brief Compute the difference between two qualifier sets.
464  friend Qualifiers operator-(Qualifiers L, Qualifiers R) {
465    L -= R;
466    return L;
467  }
468
469  std::string getAsString() const;
470  std::string getAsString(const PrintingPolicy &Policy) const;
471
472  bool isEmptyWhenPrinted(const PrintingPolicy &Policy) const;
473  void print(raw_ostream &OS, const PrintingPolicy &Policy,
474             bool appendSpaceIfNonEmpty = false) const;
475
476  void Profile(llvm::FoldingSetNodeID &ID) const {
477    ID.AddInteger(Mask);
478  }
479
480private:
481
482  // bits:     |0 1 2|3 .. 4|5  ..  7|8   ...   31|
483  //           |C R V|GCAttr|Lifetime|AddressSpace|
484  uint32_t Mask;
485
486  static const uint32_t GCAttrMask = 0x18;
487  static const uint32_t GCAttrShift = 3;
488  static const uint32_t LifetimeMask = 0xE0;
489  static const uint32_t LifetimeShift = 5;
490  static const uint32_t AddressSpaceMask = ~(CVRMask|GCAttrMask|LifetimeMask);
491  static const uint32_t AddressSpaceShift = 8;
492};
493
494/// A std::pair-like structure for storing a qualified type split
495/// into its local qualifiers and its locally-unqualified type.
496struct SplitQualType {
497  /// The locally-unqualified type.
498  const Type *Ty;
499
500  /// The local qualifiers.
501  Qualifiers Quals;
502
503  SplitQualType() : Ty(0), Quals() {}
504  SplitQualType(const Type *ty, Qualifiers qs) : Ty(ty), Quals(qs) {}
505
506  SplitQualType getSingleStepDesugaredType() const; // end of this file
507
508  // Make std::tie work.
509  std::pair<const Type *,Qualifiers> asPair() const {
510    return std::pair<const Type *, Qualifiers>(Ty, Quals);
511  }
512
513  friend bool operator==(SplitQualType a, SplitQualType b) {
514    return a.Ty == b.Ty && a.Quals == b.Quals;
515  }
516  friend bool operator!=(SplitQualType a, SplitQualType b) {
517    return a.Ty != b.Ty || a.Quals != b.Quals;
518  }
519};
520
521/// QualType - For efficiency, we don't store CV-qualified types as nodes on
522/// their own: instead each reference to a type stores the qualifiers.  This
523/// greatly reduces the number of nodes we need to allocate for types (for
524/// example we only need one for 'int', 'const int', 'volatile int',
525/// 'const volatile int', etc).
526///
527/// As an added efficiency bonus, instead of making this a pair, we
528/// just store the two bits we care about in the low bits of the
529/// pointer.  To handle the packing/unpacking, we make QualType be a
530/// simple wrapper class that acts like a smart pointer.  A third bit
531/// indicates whether there are extended qualifiers present, in which
532/// case the pointer points to a special structure.
533class QualType {
534  // Thankfully, these are efficiently composable.
535  llvm::PointerIntPair<llvm::PointerUnion<const Type*,const ExtQuals*>,
536                       Qualifiers::FastWidth> Value;
537
538  const ExtQuals *getExtQualsUnsafe() const {
539    return Value.getPointer().get<const ExtQuals*>();
540  }
541
542  const Type *getTypePtrUnsafe() const {
543    return Value.getPointer().get<const Type*>();
544  }
545
546  const ExtQualsTypeCommonBase *getCommonPtr() const {
547    assert(!isNull() && "Cannot retrieve a NULL type pointer");
548    uintptr_t CommonPtrVal
549      = reinterpret_cast<uintptr_t>(Value.getOpaqueValue());
550    CommonPtrVal &= ~(uintptr_t)((1 << TypeAlignmentInBits) - 1);
551    return reinterpret_cast<ExtQualsTypeCommonBase*>(CommonPtrVal);
552  }
553
554  friend class QualifierCollector;
555public:
556  QualType() {}
557
558  QualType(const Type *Ptr, unsigned Quals)
559    : Value(Ptr, Quals) {}
560  QualType(const ExtQuals *Ptr, unsigned Quals)
561    : Value(Ptr, Quals) {}
562
563  unsigned getLocalFastQualifiers() const { return Value.getInt(); }
564  void setLocalFastQualifiers(unsigned Quals) { Value.setInt(Quals); }
565
566  /// Retrieves a pointer to the underlying (unqualified) type.
567  ///
568  /// This function requires that the type not be NULL. If the type might be
569  /// NULL, use the (slightly less efficient) \c getTypePtrOrNull().
570  const Type *getTypePtr() const;
571
572  const Type *getTypePtrOrNull() const;
573
574  /// Retrieves a pointer to the name of the base type.
575  const IdentifierInfo *getBaseTypeIdentifier() const;
576
577  /// Divides a QualType into its unqualified type and a set of local
578  /// qualifiers.
579  SplitQualType split() const;
580
581  void *getAsOpaquePtr() const { return Value.getOpaqueValue(); }
582  static QualType getFromOpaquePtr(const void *Ptr) {
583    QualType T;
584    T.Value.setFromOpaqueValue(const_cast<void*>(Ptr));
585    return T;
586  }
587
588  const Type &operator*() const {
589    return *getTypePtr();
590  }
591
592  const Type *operator->() const {
593    return getTypePtr();
594  }
595
596  bool isCanonical() const;
597  bool isCanonicalAsParam() const;
598
599  /// isNull - Return true if this QualType doesn't point to a type yet.
600  bool isNull() const {
601    return Value.getPointer().isNull();
602  }
603
604  /// \brief Determine whether this particular QualType instance has the
605  /// "const" qualifier set, without looking through typedefs that may have
606  /// added "const" at a different level.
607  bool isLocalConstQualified() const {
608    return (getLocalFastQualifiers() & Qualifiers::Const);
609  }
610
611  /// \brief Determine whether this type is const-qualified.
612  bool isConstQualified() const;
613
614  /// \brief Determine whether this particular QualType instance has the
615  /// "restrict" qualifier set, without looking through typedefs that may have
616  /// added "restrict" at a different level.
617  bool isLocalRestrictQualified() const {
618    return (getLocalFastQualifiers() & Qualifiers::Restrict);
619  }
620
621  /// \brief Determine whether this type is restrict-qualified.
622  bool isRestrictQualified() const;
623
624  /// \brief Determine whether this particular QualType instance has the
625  /// "volatile" qualifier set, without looking through typedefs that may have
626  /// added "volatile" at a different level.
627  bool isLocalVolatileQualified() const {
628    return (getLocalFastQualifiers() & Qualifiers::Volatile);
629  }
630
631  /// \brief Determine whether this type is volatile-qualified.
632  bool isVolatileQualified() const;
633
634  /// \brief Determine whether this particular QualType instance has any
635  /// qualifiers, without looking through any typedefs that might add
636  /// qualifiers at a different level.
637  bool hasLocalQualifiers() const {
638    return getLocalFastQualifiers() || hasLocalNonFastQualifiers();
639  }
640
641  /// \brief Determine whether this type has any qualifiers.
642  bool hasQualifiers() const;
643
644  /// \brief Determine whether this particular QualType instance has any
645  /// "non-fast" qualifiers, e.g., those that are stored in an ExtQualType
646  /// instance.
647  bool hasLocalNonFastQualifiers() const {
648    return Value.getPointer().is<const ExtQuals*>();
649  }
650
651  /// \brief Retrieve the set of qualifiers local to this particular QualType
652  /// instance, not including any qualifiers acquired through typedefs or
653  /// other sugar.
654  Qualifiers getLocalQualifiers() const;
655
656  /// \brief Retrieve the set of qualifiers applied to this type.
657  Qualifiers getQualifiers() const;
658
659  /// \brief Retrieve the set of CVR (const-volatile-restrict) qualifiers
660  /// local to this particular QualType instance, not including any qualifiers
661  /// acquired through typedefs or other sugar.
662  unsigned getLocalCVRQualifiers() const {
663    return getLocalFastQualifiers();
664  }
665
666  /// \brief Retrieve the set of CVR (const-volatile-restrict) qualifiers
667  /// applied to this type.
668  unsigned getCVRQualifiers() const;
669
670  bool isConstant(ASTContext& Ctx) const {
671    return QualType::isConstant(*this, Ctx);
672  }
673
674  /// \brief Determine whether this is a Plain Old Data (POD) type (C++ 3.9p10).
675  bool isPODType(ASTContext &Context) const;
676
677  /// isCXX98PODType() - Return true if this is a POD type according to the
678  /// rules of the C++98 standard, regardless of the current compilation's
679  /// language.
680  bool isCXX98PODType(ASTContext &Context) const;
681
682  /// isCXX11PODType() - Return true if this is a POD type according to the
683  /// more relaxed rules of the C++11 standard, regardless of the current
684  /// compilation's language.
685  /// (C++0x [basic.types]p9)
686  bool isCXX11PODType(ASTContext &Context) const;
687
688  /// isTrivialType - Return true if this is a trivial type
689  /// (C++0x [basic.types]p9)
690  bool isTrivialType(ASTContext &Context) const;
691
692  /// isTriviallyCopyableType - Return true if this is a trivially
693  /// copyable type (C++0x [basic.types]p9)
694  bool isTriviallyCopyableType(ASTContext &Context) const;
695
696  // Don't promise in the API that anything besides 'const' can be
697  // easily added.
698
699  /// addConst - add the specified type qualifier to this QualType.
700  void addConst() {
701    addFastQualifiers(Qualifiers::Const);
702  }
703  QualType withConst() const {
704    return withFastQualifiers(Qualifiers::Const);
705  }
706
707  /// addVolatile - add the specified type qualifier to this QualType.
708  void addVolatile() {
709    addFastQualifiers(Qualifiers::Volatile);
710  }
711  QualType withVolatile() const {
712    return withFastQualifiers(Qualifiers::Volatile);
713  }
714
715  /// Add the restrict qualifier to this QualType.
716  void addRestrict() {
717    addFastQualifiers(Qualifiers::Restrict);
718  }
719  QualType withRestrict() const {
720    return withFastQualifiers(Qualifiers::Restrict);
721  }
722
723  QualType withCVRQualifiers(unsigned CVR) const {
724    return withFastQualifiers(CVR);
725  }
726
727  void addFastQualifiers(unsigned TQs) {
728    assert(!(TQs & ~Qualifiers::FastMask)
729           && "non-fast qualifier bits set in mask!");
730    Value.setInt(Value.getInt() | TQs);
731  }
732
733  void removeLocalConst();
734  void removeLocalVolatile();
735  void removeLocalRestrict();
736  void removeLocalCVRQualifiers(unsigned Mask);
737
738  void removeLocalFastQualifiers() { Value.setInt(0); }
739  void removeLocalFastQualifiers(unsigned Mask) {
740    assert(!(Mask & ~Qualifiers::FastMask) && "mask has non-fast qualifiers");
741    Value.setInt(Value.getInt() & ~Mask);
742  }
743
744  // Creates a type with the given qualifiers in addition to any
745  // qualifiers already on this type.
746  QualType withFastQualifiers(unsigned TQs) const {
747    QualType T = *this;
748    T.addFastQualifiers(TQs);
749    return T;
750  }
751
752  // Creates a type with exactly the given fast qualifiers, removing
753  // any existing fast qualifiers.
754  QualType withExactLocalFastQualifiers(unsigned TQs) const {
755    return withoutLocalFastQualifiers().withFastQualifiers(TQs);
756  }
757
758  // Removes fast qualifiers, but leaves any extended qualifiers in place.
759  QualType withoutLocalFastQualifiers() const {
760    QualType T = *this;
761    T.removeLocalFastQualifiers();
762    return T;
763  }
764
765  QualType getCanonicalType() const;
766
767  /// \brief Return this type with all of the instance-specific qualifiers
768  /// removed, but without removing any qualifiers that may have been applied
769  /// through typedefs.
770  QualType getLocalUnqualifiedType() const { return QualType(getTypePtr(), 0); }
771
772  /// \brief Retrieve the unqualified variant of the given type,
773  /// removing as little sugar as possible.
774  ///
775  /// This routine looks through various kinds of sugar to find the
776  /// least-desugared type that is unqualified. For example, given:
777  ///
778  /// \code
779  /// typedef int Integer;
780  /// typedef const Integer CInteger;
781  /// typedef CInteger DifferenceType;
782  /// \endcode
783  ///
784  /// Executing \c getUnqualifiedType() on the type \c DifferenceType will
785  /// desugar until we hit the type \c Integer, which has no qualifiers on it.
786  ///
787  /// The resulting type might still be qualified if it's sugar for an array
788  /// type.  To strip qualifiers even from within a sugared array type, use
789  /// ASTContext::getUnqualifiedArrayType.
790  inline QualType getUnqualifiedType() const;
791
792  /// getSplitUnqualifiedType - Retrieve the unqualified variant of the
793  /// given type, removing as little sugar as possible.
794  ///
795  /// Like getUnqualifiedType(), but also returns the set of
796  /// qualifiers that were built up.
797  ///
798  /// The resulting type might still be qualified if it's sugar for an array
799  /// type.  To strip qualifiers even from within a sugared array type, use
800  /// ASTContext::getUnqualifiedArrayType.
801  inline SplitQualType getSplitUnqualifiedType() const;
802
803  /// \brief Determine whether this type is more qualified than the other
804  /// given type, requiring exact equality for non-CVR qualifiers.
805  bool isMoreQualifiedThan(QualType Other) const;
806
807  /// \brief Determine whether this type is at least as qualified as the other
808  /// given type, requiring exact equality for non-CVR qualifiers.
809  bool isAtLeastAsQualifiedAs(QualType Other) const;
810
811  QualType getNonReferenceType() const;
812
813  /// \brief Determine the type of a (typically non-lvalue) expression with the
814  /// specified result type.
815  ///
816  /// This routine should be used for expressions for which the return type is
817  /// explicitly specified (e.g., in a cast or call) and isn't necessarily
818  /// an lvalue. It removes a top-level reference (since there are no
819  /// expressions of reference type) and deletes top-level cvr-qualifiers
820  /// from non-class types (in C++) or all types (in C).
821  QualType getNonLValueExprType(const ASTContext &Context) const;
822
823  /// getDesugaredType - Return the specified type with any "sugar" removed from
824  /// the type.  This takes off typedefs, typeof's etc.  If the outer level of
825  /// the type is already concrete, it returns it unmodified.  This is similar
826  /// to getting the canonical type, but it doesn't remove *all* typedefs.  For
827  /// example, it returns "T*" as "T*", (not as "int*"), because the pointer is
828  /// concrete.
829  ///
830  /// Qualifiers are left in place.
831  QualType getDesugaredType(const ASTContext &Context) const {
832    return getDesugaredType(*this, Context);
833  }
834
835  SplitQualType getSplitDesugaredType() const {
836    return getSplitDesugaredType(*this);
837  }
838
839  /// \brief Return the specified type with one level of "sugar" removed from
840  /// the type.
841  ///
842  /// This routine takes off the first typedef, typeof, etc. If the outer level
843  /// of the type is already concrete, it returns it unmodified.
844  QualType getSingleStepDesugaredType(const ASTContext &Context) const {
845    return getSingleStepDesugaredTypeImpl(*this, Context);
846  }
847
848  /// IgnoreParens - Returns the specified type after dropping any
849  /// outer-level parentheses.
850  QualType IgnoreParens() const {
851    if (isa<ParenType>(*this))
852      return QualType::IgnoreParens(*this);
853    return *this;
854  }
855
856  /// operator==/!= - Indicate whether the specified types and qualifiers are
857  /// identical.
858  friend bool operator==(const QualType &LHS, const QualType &RHS) {
859    return LHS.Value == RHS.Value;
860  }
861  friend bool operator!=(const QualType &LHS, const QualType &RHS) {
862    return LHS.Value != RHS.Value;
863  }
864  std::string getAsString() const {
865    return getAsString(split());
866  }
867  static std::string getAsString(SplitQualType split) {
868    return getAsString(split.Ty, split.Quals);
869  }
870  static std::string getAsString(const Type *ty, Qualifiers qs);
871
872  std::string getAsString(const PrintingPolicy &Policy) const;
873
874  void print(raw_ostream &OS, const PrintingPolicy &Policy,
875             const Twine &PlaceHolder = Twine()) const {
876    print(split(), OS, Policy, PlaceHolder);
877  }
878  static void print(SplitQualType split, raw_ostream &OS,
879                    const PrintingPolicy &policy, const Twine &PlaceHolder) {
880    return print(split.Ty, split.Quals, OS, policy, PlaceHolder);
881  }
882  static void print(const Type *ty, Qualifiers qs,
883                    raw_ostream &OS, const PrintingPolicy &policy,
884                    const Twine &PlaceHolder);
885
886  void getAsStringInternal(std::string &Str,
887                           const PrintingPolicy &Policy) const {
888    return getAsStringInternal(split(), Str, Policy);
889  }
890  static void getAsStringInternal(SplitQualType split, std::string &out,
891                                  const PrintingPolicy &policy) {
892    return getAsStringInternal(split.Ty, split.Quals, out, policy);
893  }
894  static void getAsStringInternal(const Type *ty, Qualifiers qs,
895                                  std::string &out,
896                                  const PrintingPolicy &policy);
897
898  class StreamedQualTypeHelper {
899    const QualType &T;
900    const PrintingPolicy &Policy;
901    const Twine &PlaceHolder;
902  public:
903    StreamedQualTypeHelper(const QualType &T, const PrintingPolicy &Policy,
904                           const Twine &PlaceHolder)
905      : T(T), Policy(Policy), PlaceHolder(PlaceHolder) { }
906
907    friend raw_ostream &operator<<(raw_ostream &OS,
908                                   const StreamedQualTypeHelper &SQT) {
909      SQT.T.print(OS, SQT.Policy, SQT.PlaceHolder);
910      return OS;
911    }
912  };
913
914  StreamedQualTypeHelper stream(const PrintingPolicy &Policy,
915                                const Twine &PlaceHolder = Twine()) const {
916    return StreamedQualTypeHelper(*this, Policy, PlaceHolder);
917  }
918
919  void dump(const char *s) const;
920  void dump() const;
921
922  void Profile(llvm::FoldingSetNodeID &ID) const {
923    ID.AddPointer(getAsOpaquePtr());
924  }
925
926  /// getAddressSpace - Return the address space of this type.
927  inline unsigned getAddressSpace() const;
928
929  /// getObjCGCAttr - Returns gc attribute of this type.
930  inline Qualifiers::GC getObjCGCAttr() const;
931
932  /// isObjCGCWeak true when Type is objc's weak.
933  bool isObjCGCWeak() const {
934    return getObjCGCAttr() == Qualifiers::Weak;
935  }
936
937  /// isObjCGCStrong true when Type is objc's strong.
938  bool isObjCGCStrong() const {
939    return getObjCGCAttr() == Qualifiers::Strong;
940  }
941
942  /// getObjCLifetime - Returns lifetime attribute of this type.
943  Qualifiers::ObjCLifetime getObjCLifetime() const {
944    return getQualifiers().getObjCLifetime();
945  }
946
947  bool hasNonTrivialObjCLifetime() const {
948    return getQualifiers().hasNonTrivialObjCLifetime();
949  }
950
951  bool hasStrongOrWeakObjCLifetime() const {
952    return getQualifiers().hasStrongOrWeakObjCLifetime();
953  }
954
955  enum DestructionKind {
956    DK_none,
957    DK_cxx_destructor,
958    DK_objc_strong_lifetime,
959    DK_objc_weak_lifetime
960  };
961
962  /// isDestructedType - nonzero if objects of this type require
963  /// non-trivial work to clean up after.  Non-zero because it's
964  /// conceivable that qualifiers (objc_gc(weak)?) could make
965  /// something require destruction.
966  DestructionKind isDestructedType() const {
967    return isDestructedTypeImpl(*this);
968  }
969
970  /// \brief Determine whether expressions of the given type are forbidden
971  /// from being lvalues in C.
972  ///
973  /// The expression types that are forbidden to be lvalues are:
974  ///   - 'void', but not qualified void
975  ///   - function types
976  ///
977  /// The exact rule here is C99 6.3.2.1:
978  ///   An lvalue is an expression with an object type or an incomplete
979  ///   type other than void.
980  bool isCForbiddenLValueType() const;
981
982private:
983  // These methods are implemented in a separate translation unit;
984  // "static"-ize them to avoid creating temporary QualTypes in the
985  // caller.
986  static bool isConstant(QualType T, ASTContext& Ctx);
987  static QualType getDesugaredType(QualType T, const ASTContext &Context);
988  static SplitQualType getSplitDesugaredType(QualType T);
989  static SplitQualType getSplitUnqualifiedTypeImpl(QualType type);
990  static QualType getSingleStepDesugaredTypeImpl(QualType type,
991                                                 const ASTContext &C);
992  static QualType IgnoreParens(QualType T);
993  static DestructionKind isDestructedTypeImpl(QualType type);
994};
995
996} // end clang.
997
998namespace llvm {
999/// Implement simplify_type for QualType, so that we can dyn_cast from QualType
1000/// to a specific Type class.
1001template<> struct simplify_type< ::clang::QualType> {
1002  typedef const ::clang::Type *SimpleType;
1003  static SimpleType getSimplifiedValue(::clang::QualType Val) {
1004    return Val.getTypePtr();
1005  }
1006};
1007
1008// Teach SmallPtrSet that QualType is "basically a pointer".
1009template<>
1010class PointerLikeTypeTraits<clang::QualType> {
1011public:
1012  static inline void *getAsVoidPointer(clang::QualType P) {
1013    return P.getAsOpaquePtr();
1014  }
1015  static inline clang::QualType getFromVoidPointer(void *P) {
1016    return clang::QualType::getFromOpaquePtr(P);
1017  }
1018  // Various qualifiers go in low bits.
1019  enum { NumLowBitsAvailable = 0 };
1020};
1021
1022} // end namespace llvm
1023
1024namespace clang {
1025
1026/// \brief Base class that is common to both the \c ExtQuals and \c Type
1027/// classes, which allows \c QualType to access the common fields between the
1028/// two.
1029///
1030class ExtQualsTypeCommonBase {
1031  ExtQualsTypeCommonBase(const Type *baseType, QualType canon)
1032    : BaseType(baseType), CanonicalType(canon) {}
1033
1034  /// \brief The "base" type of an extended qualifiers type (\c ExtQuals) or
1035  /// a self-referential pointer (for \c Type).
1036  ///
1037  /// This pointer allows an efficient mapping from a QualType to its
1038  /// underlying type pointer.
1039  const Type *const BaseType;
1040
1041  /// \brief The canonical type of this type.  A QualType.
1042  QualType CanonicalType;
1043
1044  friend class QualType;
1045  friend class Type;
1046  friend class ExtQuals;
1047};
1048
1049/// ExtQuals - We can encode up to four bits in the low bits of a
1050/// type pointer, but there are many more type qualifiers that we want
1051/// to be able to apply to an arbitrary type.  Therefore we have this
1052/// struct, intended to be heap-allocated and used by QualType to
1053/// store qualifiers.
1054///
1055/// The current design tags the 'const', 'restrict', and 'volatile' qualifiers
1056/// in three low bits on the QualType pointer; a fourth bit records whether
1057/// the pointer is an ExtQuals node. The extended qualifiers (address spaces,
1058/// Objective-C GC attributes) are much more rare.
1059class ExtQuals : public ExtQualsTypeCommonBase, public llvm::FoldingSetNode {
1060  // NOTE: changing the fast qualifiers should be straightforward as
1061  // long as you don't make 'const' non-fast.
1062  // 1. Qualifiers:
1063  //    a) Modify the bitmasks (Qualifiers::TQ and DeclSpec::TQ).
1064  //       Fast qualifiers must occupy the low-order bits.
1065  //    b) Update Qualifiers::FastWidth and FastMask.
1066  // 2. QualType:
1067  //    a) Update is{Volatile,Restrict}Qualified(), defined inline.
1068  //    b) Update remove{Volatile,Restrict}, defined near the end of
1069  //       this header.
1070  // 3. ASTContext:
1071  //    a) Update get{Volatile,Restrict}Type.
1072
1073  /// Quals - the immutable set of qualifiers applied by this
1074  /// node;  always contains extended qualifiers.
1075  Qualifiers Quals;
1076
1077  ExtQuals *this_() { return this; }
1078
1079public:
1080  ExtQuals(const Type *baseType, QualType canon, Qualifiers quals)
1081    : ExtQualsTypeCommonBase(baseType,
1082                             canon.isNull() ? QualType(this_(), 0) : canon),
1083      Quals(quals)
1084  {
1085    assert(Quals.hasNonFastQualifiers()
1086           && "ExtQuals created with no fast qualifiers");
1087    assert(!Quals.hasFastQualifiers()
1088           && "ExtQuals created with fast qualifiers");
1089  }
1090
1091  Qualifiers getQualifiers() const { return Quals; }
1092
1093  bool hasObjCGCAttr() const { return Quals.hasObjCGCAttr(); }
1094  Qualifiers::GC getObjCGCAttr() const { return Quals.getObjCGCAttr(); }
1095
1096  bool hasObjCLifetime() const { return Quals.hasObjCLifetime(); }
1097  Qualifiers::ObjCLifetime getObjCLifetime() const {
1098    return Quals.getObjCLifetime();
1099  }
1100
1101  bool hasAddressSpace() const { return Quals.hasAddressSpace(); }
1102  unsigned getAddressSpace() const { return Quals.getAddressSpace(); }
1103
1104  const Type *getBaseType() const { return BaseType; }
1105
1106public:
1107  void Profile(llvm::FoldingSetNodeID &ID) const {
1108    Profile(ID, getBaseType(), Quals);
1109  }
1110  static void Profile(llvm::FoldingSetNodeID &ID,
1111                      const Type *BaseType,
1112                      Qualifiers Quals) {
1113    assert(!Quals.hasFastQualifiers() && "fast qualifiers in ExtQuals hash!");
1114    ID.AddPointer(BaseType);
1115    Quals.Profile(ID);
1116  }
1117};
1118
1119/// \brief The kind of C++0x ref-qualifier associated with a function type,
1120/// which determines whether a member function's "this" object can be an
1121/// lvalue, rvalue, or neither.
1122enum RefQualifierKind {
1123  /// \brief No ref-qualifier was provided.
1124  RQ_None = 0,
1125  /// \brief An lvalue ref-qualifier was provided (\c &).
1126  RQ_LValue,
1127  /// \brief An rvalue ref-qualifier was provided (\c &&).
1128  RQ_RValue
1129};
1130
1131/// Type - This is the base class of the type hierarchy.  A central concept
1132/// with types is that each type always has a canonical type.  A canonical type
1133/// is the type with any typedef names stripped out of it or the types it
1134/// references.  For example, consider:
1135///
1136///  typedef int  foo;
1137///  typedef foo* bar;
1138///    'int *'    'foo *'    'bar'
1139///
1140/// There will be a Type object created for 'int'.  Since int is canonical, its
1141/// canonicaltype pointer points to itself.  There is also a Type for 'foo' (a
1142/// TypedefType).  Its CanonicalType pointer points to the 'int' Type.  Next
1143/// there is a PointerType that represents 'int*', which, like 'int', is
1144/// canonical.  Finally, there is a PointerType type for 'foo*' whose canonical
1145/// type is 'int*', and there is a TypedefType for 'bar', whose canonical type
1146/// is also 'int*'.
1147///
1148/// Non-canonical types are useful for emitting diagnostics, without losing
1149/// information about typedefs being used.  Canonical types are useful for type
1150/// comparisons (they allow by-pointer equality tests) and useful for reasoning
1151/// about whether something has a particular form (e.g. is a function type),
1152/// because they implicitly, recursively, strip all typedefs out of a type.
1153///
1154/// Types, once created, are immutable.
1155///
1156class Type : public ExtQualsTypeCommonBase {
1157public:
1158  enum TypeClass {
1159#define TYPE(Class, Base) Class,
1160#define LAST_TYPE(Class) TypeLast = Class,
1161#define ABSTRACT_TYPE(Class, Base)
1162#include "clang/AST/TypeNodes.def"
1163    TagFirst = Record, TagLast = Enum
1164  };
1165
1166private:
1167  Type(const Type &) LLVM_DELETED_FUNCTION;
1168  void operator=(const Type &) LLVM_DELETED_FUNCTION;
1169
1170  /// Bitfields required by the Type class.
1171  class TypeBitfields {
1172    friend class Type;
1173    template <class T> friend class TypePropertyCache;
1174
1175    /// TypeClass bitfield - Enum that specifies what subclass this belongs to.
1176    unsigned TC : 8;
1177
1178    /// Dependent - Whether this type is a dependent type (C++ [temp.dep.type]).
1179    unsigned Dependent : 1;
1180
1181    /// \brief Whether this type somehow involves a template parameter, even
1182    /// if the resolution of the type does not depend on a template parameter.
1183    unsigned InstantiationDependent : 1;
1184
1185    /// \brief Whether this type is a variably-modified type (C99 6.7.5).
1186    unsigned VariablyModified : 1;
1187
1188    /// \brief Whether this type contains an unexpanded parameter pack
1189    /// (for C++0x variadic templates).
1190    unsigned ContainsUnexpandedParameterPack : 1;
1191
1192    /// \brief True if the cache (i.e. the bitfields here starting with
1193    /// 'Cache') is valid.
1194    mutable unsigned CacheValid : 1;
1195
1196    /// \brief Linkage of this type.
1197    mutable unsigned CachedLinkage : 3;
1198
1199    /// \brief Whether this type involves and local or unnamed types.
1200    mutable unsigned CachedLocalOrUnnamed : 1;
1201
1202    /// \brief FromAST - Whether this type comes from an AST file.
1203    mutable unsigned FromAST : 1;
1204
1205    bool isCacheValid() const {
1206      return CacheValid;
1207    }
1208    Linkage getLinkage() const {
1209      assert(isCacheValid() && "getting linkage from invalid cache");
1210      return static_cast<Linkage>(CachedLinkage);
1211    }
1212    bool hasLocalOrUnnamedType() const {
1213      assert(isCacheValid() && "getting linkage from invalid cache");
1214      return CachedLocalOrUnnamed;
1215    }
1216  };
1217  enum { NumTypeBits = 18 };
1218
1219protected:
1220  // These classes allow subclasses to somewhat cleanly pack bitfields
1221  // into Type.
1222
1223  class ArrayTypeBitfields {
1224    friend class ArrayType;
1225
1226    unsigned : NumTypeBits;
1227
1228    /// IndexTypeQuals - CVR qualifiers from declarations like
1229    /// 'int X[static restrict 4]'. For function parameters only.
1230    unsigned IndexTypeQuals : 3;
1231
1232    /// SizeModifier - storage class qualifiers from declarations like
1233    /// 'int X[static restrict 4]'. For function parameters only.
1234    /// Actually an ArrayType::ArraySizeModifier.
1235    unsigned SizeModifier : 3;
1236  };
1237
1238  class BuiltinTypeBitfields {
1239    friend class BuiltinType;
1240
1241    unsigned : NumTypeBits;
1242
1243    /// The kind (BuiltinType::Kind) of builtin type this is.
1244    unsigned Kind : 8;
1245  };
1246
1247  class FunctionTypeBitfields {
1248    friend class FunctionType;
1249
1250    unsigned : NumTypeBits;
1251
1252    /// Extra information which affects how the function is called, like
1253    /// regparm and the calling convention.
1254    unsigned ExtInfo : 9;
1255
1256    /// TypeQuals - Used only by FunctionProtoType, put here to pack with the
1257    /// other bitfields.
1258    /// The qualifiers are part of FunctionProtoType because...
1259    ///
1260    /// C++ 8.3.5p4: The return type, the parameter type list and the
1261    /// cv-qualifier-seq, [...], are part of the function type.
1262    unsigned TypeQuals : 3;
1263  };
1264
1265  class ObjCObjectTypeBitfields {
1266    friend class ObjCObjectType;
1267
1268    unsigned : NumTypeBits;
1269
1270    /// NumProtocols - The number of protocols stored directly on this
1271    /// object type.
1272    unsigned NumProtocols : 32 - NumTypeBits;
1273  };
1274
1275  class ReferenceTypeBitfields {
1276    friend class ReferenceType;
1277
1278    unsigned : NumTypeBits;
1279
1280    /// True if the type was originally spelled with an lvalue sigil.
1281    /// This is never true of rvalue references but can also be false
1282    /// on lvalue references because of C++0x [dcl.typedef]p9,
1283    /// as follows:
1284    ///
1285    ///   typedef int &ref;    // lvalue, spelled lvalue
1286    ///   typedef int &&rvref; // rvalue
1287    ///   ref &a;              // lvalue, inner ref, spelled lvalue
1288    ///   ref &&a;             // lvalue, inner ref
1289    ///   rvref &a;            // lvalue, inner ref, spelled lvalue
1290    ///   rvref &&a;           // rvalue, inner ref
1291    unsigned SpelledAsLValue : 1;
1292
1293    /// True if the inner type is a reference type.  This only happens
1294    /// in non-canonical forms.
1295    unsigned InnerRef : 1;
1296  };
1297
1298  class TypeWithKeywordBitfields {
1299    friend class TypeWithKeyword;
1300
1301    unsigned : NumTypeBits;
1302
1303    /// An ElaboratedTypeKeyword.  8 bits for efficient access.
1304    unsigned Keyword : 8;
1305  };
1306
1307  class VectorTypeBitfields {
1308    friend class VectorType;
1309
1310    unsigned : NumTypeBits;
1311
1312    /// VecKind - The kind of vector, either a generic vector type or some
1313    /// target-specific vector type such as for AltiVec or Neon.
1314    unsigned VecKind : 3;
1315
1316    /// NumElements - The number of elements in the vector.
1317    unsigned NumElements : 29 - NumTypeBits;
1318
1319    enum { MaxNumElements = (1 << (29 - NumTypeBits)) - 1 };
1320  };
1321
1322  class AttributedTypeBitfields {
1323    friend class AttributedType;
1324
1325    unsigned : NumTypeBits;
1326
1327    /// AttrKind - an AttributedType::Kind
1328    unsigned AttrKind : 32 - NumTypeBits;
1329  };
1330
1331  class AutoTypeBitfields {
1332    friend class AutoType;
1333
1334    unsigned : NumTypeBits;
1335
1336    /// Was this placeholder type spelled as 'decltype(auto)'?
1337    unsigned IsDecltypeAuto : 1;
1338  };
1339
1340  union {
1341    TypeBitfields TypeBits;
1342    ArrayTypeBitfields ArrayTypeBits;
1343    AttributedTypeBitfields AttributedTypeBits;
1344    AutoTypeBitfields AutoTypeBits;
1345    BuiltinTypeBitfields BuiltinTypeBits;
1346    FunctionTypeBitfields FunctionTypeBits;
1347    ObjCObjectTypeBitfields ObjCObjectTypeBits;
1348    ReferenceTypeBitfields ReferenceTypeBits;
1349    TypeWithKeywordBitfields TypeWithKeywordBits;
1350    VectorTypeBitfields VectorTypeBits;
1351  };
1352
1353private:
1354  /// \brief Set whether this type comes from an AST file.
1355  void setFromAST(bool V = true) const {
1356    TypeBits.FromAST = V;
1357  }
1358
1359  template <class T> friend class TypePropertyCache;
1360
1361protected:
1362  // silence VC++ warning C4355: 'this' : used in base member initializer list
1363  Type *this_() { return this; }
1364  Type(TypeClass tc, QualType canon, bool Dependent,
1365       bool InstantiationDependent, bool VariablyModified,
1366       bool ContainsUnexpandedParameterPack)
1367    : ExtQualsTypeCommonBase(this,
1368                             canon.isNull() ? QualType(this_(), 0) : canon) {
1369    TypeBits.TC = tc;
1370    TypeBits.Dependent = Dependent;
1371    TypeBits.InstantiationDependent = Dependent || InstantiationDependent;
1372    TypeBits.VariablyModified = VariablyModified;
1373    TypeBits.ContainsUnexpandedParameterPack = ContainsUnexpandedParameterPack;
1374    TypeBits.CacheValid = false;
1375    TypeBits.CachedLocalOrUnnamed = false;
1376    TypeBits.CachedLinkage = NoLinkage;
1377    TypeBits.FromAST = false;
1378  }
1379  friend class ASTContext;
1380
1381  void setDependent(bool D = true) {
1382    TypeBits.Dependent = D;
1383    if (D)
1384      TypeBits.InstantiationDependent = true;
1385  }
1386  void setInstantiationDependent(bool D = true) {
1387    TypeBits.InstantiationDependent = D; }
1388  void setVariablyModified(bool VM = true) { TypeBits.VariablyModified = VM;
1389  }
1390  void setContainsUnexpandedParameterPack(bool PP = true) {
1391    TypeBits.ContainsUnexpandedParameterPack = PP;
1392  }
1393
1394public:
1395  TypeClass getTypeClass() const { return static_cast<TypeClass>(TypeBits.TC); }
1396
1397  /// \brief Whether this type comes from an AST file.
1398  bool isFromAST() const { return TypeBits.FromAST; }
1399
1400  /// \brief Whether this type is or contains an unexpanded parameter
1401  /// pack, used to support C++0x variadic templates.
1402  ///
1403  /// A type that contains a parameter pack shall be expanded by the
1404  /// ellipsis operator at some point. For example, the typedef in the
1405  /// following example contains an unexpanded parameter pack 'T':
1406  ///
1407  /// \code
1408  /// template<typename ...T>
1409  /// struct X {
1410  ///   typedef T* pointer_types; // ill-formed; T is a parameter pack.
1411  /// };
1412  /// \endcode
1413  ///
1414  /// Note that this routine does not specify which
1415  bool containsUnexpandedParameterPack() const {
1416    return TypeBits.ContainsUnexpandedParameterPack;
1417  }
1418
1419  /// Determines if this type would be canonical if it had no further
1420  /// qualification.
1421  bool isCanonicalUnqualified() const {
1422    return CanonicalType == QualType(this, 0);
1423  }
1424
1425  /// Pull a single level of sugar off of this locally-unqualified type.
1426  /// Users should generally prefer SplitQualType::getSingleStepDesugaredType()
1427  /// or QualType::getSingleStepDesugaredType(const ASTContext&).
1428  QualType getLocallyUnqualifiedSingleStepDesugaredType() const;
1429
1430  /// Types are partitioned into 3 broad categories (C99 6.2.5p1):
1431  /// object types, function types, and incomplete types.
1432
1433  /// isIncompleteType - Return true if this is an incomplete type.
1434  /// A type that can describe objects, but which lacks information needed to
1435  /// determine its size (e.g. void, or a fwd declared struct). Clients of this
1436  /// routine will need to determine if the size is actually required.
1437  ///
1438  /// \brief Def If non-NULL, and the type refers to some kind of declaration
1439  /// that can be completed (such as a C struct, C++ class, or Objective-C
1440  /// class), will be set to the declaration.
1441  bool isIncompleteType(NamedDecl **Def = 0) const;
1442
1443  /// isIncompleteOrObjectType - Return true if this is an incomplete or object
1444  /// type, in other words, not a function type.
1445  bool isIncompleteOrObjectType() const {
1446    return !isFunctionType();
1447  }
1448
1449  /// \brief Determine whether this type is an object type.
1450  bool isObjectType() const {
1451    // C++ [basic.types]p8:
1452    //   An object type is a (possibly cv-qualified) type that is not a
1453    //   function type, not a reference type, and not a void type.
1454    return !isReferenceType() && !isFunctionType() && !isVoidType();
1455  }
1456
1457  /// isLiteralType - Return true if this is a literal type
1458  /// (C++11 [basic.types]p10)
1459  bool isLiteralType(const ASTContext &Ctx) const;
1460
1461  /// \brief Test if this type is a standard-layout type.
1462  /// (C++0x [basic.type]p9)
1463  bool isStandardLayoutType() const;
1464
1465  /// Helper methods to distinguish type categories. All type predicates
1466  /// operate on the canonical type, ignoring typedefs and qualifiers.
1467
1468  /// isBuiltinType - returns true if the type is a builtin type.
1469  bool isBuiltinType() const;
1470
1471  /// isSpecificBuiltinType - Test for a particular builtin type.
1472  bool isSpecificBuiltinType(unsigned K) const;
1473
1474  /// isPlaceholderType - Test for a type which does not represent an
1475  /// actual type-system type but is instead used as a placeholder for
1476  /// various convenient purposes within Clang.  All such types are
1477  /// BuiltinTypes.
1478  bool isPlaceholderType() const;
1479  const BuiltinType *getAsPlaceholderType() const;
1480
1481  /// isSpecificPlaceholderType - Test for a specific placeholder type.
1482  bool isSpecificPlaceholderType(unsigned K) const;
1483
1484  /// isNonOverloadPlaceholderType - Test for a placeholder type
1485  /// other than Overload;  see BuiltinType::isNonOverloadPlaceholderType.
1486  bool isNonOverloadPlaceholderType() const;
1487
1488  /// isIntegerType() does *not* include complex integers (a GCC extension).
1489  /// isComplexIntegerType() can be used to test for complex integers.
1490  bool isIntegerType() const;     // C99 6.2.5p17 (int, char, bool, enum)
1491  bool isEnumeralType() const;
1492  bool isBooleanType() const;
1493  bool isCharType() const;
1494  bool isWideCharType() const;
1495  bool isChar16Type() const;
1496  bool isChar32Type() const;
1497  bool isAnyCharacterType() const;
1498  bool isIntegralType(ASTContext &Ctx) const;
1499
1500  /// \brief Determine whether this type is an integral or enumeration type.
1501  bool isIntegralOrEnumerationType() const;
1502  /// \brief Determine whether this type is an integral or unscoped enumeration
1503  /// type.
1504  bool isIntegralOrUnscopedEnumerationType() const;
1505
1506  /// Floating point categories.
1507  bool isRealFloatingType() const; // C99 6.2.5p10 (float, double, long double)
1508  /// isComplexType() does *not* include complex integers (a GCC extension).
1509  /// isComplexIntegerType() can be used to test for complex integers.
1510  bool isComplexType() const;      // C99 6.2.5p11 (complex)
1511  bool isAnyComplexType() const;   // C99 6.2.5p11 (complex) + Complex Int.
1512  bool isFloatingType() const;     // C99 6.2.5p11 (real floating + complex)
1513  bool isHalfType() const;         // OpenCL 6.1.1.1, NEON (IEEE 754-2008 half)
1514  bool isRealType() const;         // C99 6.2.5p17 (real floating + integer)
1515  bool isArithmeticType() const;   // C99 6.2.5p18 (integer + floating)
1516  bool isVoidType() const;         // C99 6.2.5p19
1517  bool isScalarType() const;       // C99 6.2.5p21 (arithmetic + pointers)
1518  bool isAggregateType() const;
1519  bool isFundamentalType() const;
1520  bool isCompoundType() const;
1521
1522  // Type Predicates: Check to see if this type is structurally the specified
1523  // type, ignoring typedefs and qualifiers.
1524  bool isFunctionType() const;
1525  bool isFunctionNoProtoType() const { return getAs<FunctionNoProtoType>(); }
1526  bool isFunctionProtoType() const { return getAs<FunctionProtoType>(); }
1527  bool isPointerType() const;
1528  bool isAnyPointerType() const;   // Any C pointer or ObjC object pointer
1529  bool isBlockPointerType() const;
1530  bool isVoidPointerType() const;
1531  bool isReferenceType() const;
1532  bool isLValueReferenceType() const;
1533  bool isRValueReferenceType() const;
1534  bool isFunctionPointerType() const;
1535  bool isMemberPointerType() const;
1536  bool isMemberFunctionPointerType() const;
1537  bool isMemberDataPointerType() const;
1538  bool isArrayType() const;
1539  bool isConstantArrayType() const;
1540  bool isIncompleteArrayType() const;
1541  bool isVariableArrayType() const;
1542  bool isDependentSizedArrayType() const;
1543  bool isRecordType() const;
1544  bool isClassType() const;
1545  bool isStructureType() const;
1546  bool isInterfaceType() const;
1547  bool isStructureOrClassType() const;
1548  bool isUnionType() const;
1549  bool isComplexIntegerType() const;            // GCC _Complex integer type.
1550  bool isVectorType() const;                    // GCC vector type.
1551  bool isExtVectorType() const;                 // Extended vector type.
1552  bool isObjCObjectPointerType() const;         // pointer to ObjC object
1553  bool isObjCRetainableType() const;            // ObjC object or block pointer
1554  bool isObjCLifetimeType() const;              // (array of)* retainable type
1555  bool isObjCIndirectLifetimeType() const;      // (pointer to)* lifetime type
1556  bool isObjCNSObjectType() const;              // __attribute__((NSObject))
1557  // FIXME: change this to 'raw' interface type, so we can used 'interface' type
1558  // for the common case.
1559  bool isObjCObjectType() const;                // NSString or typeof(*(id)0)
1560  bool isObjCQualifiedInterfaceType() const;    // NSString<foo>
1561  bool isObjCQualifiedIdType() const;           // id<foo>
1562  bool isObjCQualifiedClassType() const;        // Class<foo>
1563  bool isObjCObjectOrInterfaceType() const;
1564  bool isObjCIdType() const;                    // id
1565  bool isObjCClassType() const;                 // Class
1566  bool isObjCSelType() const;                 // Class
1567  bool isObjCBuiltinType() const;               // 'id' or 'Class'
1568  bool isObjCARCBridgableType() const;
1569  bool isCARCBridgableType() const;
1570  bool isTemplateTypeParmType() const;          // C++ template type parameter
1571  bool isNullPtrType() const;                   // C++0x nullptr_t
1572  bool isAtomicType() const;                    // C11 _Atomic()
1573
1574  bool isImage1dT() const;                      // OpenCL image1d_t
1575  bool isImage1dArrayT() const;                 // OpenCL image1d_array_t
1576  bool isImage1dBufferT() const;                // OpenCL image1d_buffer_t
1577  bool isImage2dT() const;                      // OpenCL image2d_t
1578  bool isImage2dArrayT() const;                 // OpenCL image2d_array_t
1579  bool isImage3dT() const;                      // OpenCL image3d_t
1580
1581  bool isImageType() const;                     // Any OpenCL image type
1582
1583  bool isSamplerT() const;                      // OpenCL sampler_t
1584  bool isEventT() const;                        // OpenCL event_t
1585
1586  bool isOpenCLSpecificType() const;            // Any OpenCL specific type
1587
1588  /// Determines if this type, which must satisfy
1589  /// isObjCLifetimeType(), is implicitly __unsafe_unretained rather
1590  /// than implicitly __strong.
1591  bool isObjCARCImplicitlyUnretainedType() const;
1592
1593  /// Return the implicit lifetime for this type, which must not be dependent.
1594  Qualifiers::ObjCLifetime getObjCARCImplicitLifetime() const;
1595
1596  enum ScalarTypeKind {
1597    STK_CPointer,
1598    STK_BlockPointer,
1599    STK_ObjCObjectPointer,
1600    STK_MemberPointer,
1601    STK_Bool,
1602    STK_Integral,
1603    STK_Floating,
1604    STK_IntegralComplex,
1605    STK_FloatingComplex
1606  };
1607  /// getScalarTypeKind - Given that this is a scalar type, classify it.
1608  ScalarTypeKind getScalarTypeKind() const;
1609
1610  /// isDependentType - Whether this type is a dependent type, meaning
1611  /// that its definition somehow depends on a template parameter
1612  /// (C++ [temp.dep.type]).
1613  bool isDependentType() const { return TypeBits.Dependent; }
1614
1615  /// \brief Determine whether this type is an instantiation-dependent type,
1616  /// meaning that the type involves a template parameter (even if the
1617  /// definition does not actually depend on the type substituted for that
1618  /// template parameter).
1619  bool isInstantiationDependentType() const {
1620    return TypeBits.InstantiationDependent;
1621  }
1622
1623  /// \brief Determine whether this type is an undeduced type, meaning that
1624  /// it somehow involves a C++11 'auto' type which has not yet been deduced.
1625  bool isUndeducedType() const;
1626
1627  /// \brief Whether this type is a variably-modified type (C99 6.7.5).
1628  bool isVariablyModifiedType() const { return TypeBits.VariablyModified; }
1629
1630  /// \brief Whether this type involves a variable-length array type
1631  /// with a definite size.
1632  bool hasSizedVLAType() const;
1633
1634  /// \brief Whether this type is or contains a local or unnamed type.
1635  bool hasUnnamedOrLocalType() const;
1636
1637  bool isOverloadableType() const;
1638
1639  /// \brief Determine wither this type is a C++ elaborated-type-specifier.
1640  bool isElaboratedTypeSpecifier() const;
1641
1642  bool canDecayToPointerType() const;
1643
1644  /// hasPointerRepresentation - Whether this type is represented
1645  /// natively as a pointer; this includes pointers, references, block
1646  /// pointers, and Objective-C interface, qualified id, and qualified
1647  /// interface types, as well as nullptr_t.
1648  bool hasPointerRepresentation() const;
1649
1650  /// hasObjCPointerRepresentation - Whether this type can represent
1651  /// an objective pointer type for the purpose of GC'ability
1652  bool hasObjCPointerRepresentation() const;
1653
1654  /// \brief Determine whether this type has an integer representation
1655  /// of some sort, e.g., it is an integer type or a vector.
1656  bool hasIntegerRepresentation() const;
1657
1658  /// \brief Determine whether this type has an signed integer representation
1659  /// of some sort, e.g., it is an signed integer type or a vector.
1660  bool hasSignedIntegerRepresentation() const;
1661
1662  /// \brief Determine whether this type has an unsigned integer representation
1663  /// of some sort, e.g., it is an unsigned integer type or a vector.
1664  bool hasUnsignedIntegerRepresentation() const;
1665
1666  /// \brief Determine whether this type has a floating-point representation
1667  /// of some sort, e.g., it is a floating-point type or a vector thereof.
1668  bool hasFloatingRepresentation() const;
1669
1670  // Type Checking Functions: Check to see if this type is structurally the
1671  // specified type, ignoring typedefs and qualifiers, and return a pointer to
1672  // the best type we can.
1673  const RecordType *getAsStructureType() const;
1674  /// NOTE: getAs*ArrayType are methods on ASTContext.
1675  const RecordType *getAsUnionType() const;
1676  const ComplexType *getAsComplexIntegerType() const; // GCC complex int type.
1677  // The following is a convenience method that returns an ObjCObjectPointerType
1678  // for object declared using an interface.
1679  const ObjCObjectPointerType *getAsObjCInterfacePointerType() const;
1680  const ObjCObjectPointerType *getAsObjCQualifiedIdType() const;
1681  const ObjCObjectPointerType *getAsObjCQualifiedClassType() const;
1682  const ObjCObjectType *getAsObjCQualifiedInterfaceType() const;
1683
1684  /// \brief Retrieves the CXXRecordDecl that this type refers to, either
1685  /// because the type is a RecordType or because it is the injected-class-name
1686  /// type of a class template or class template partial specialization.
1687  CXXRecordDecl *getAsCXXRecordDecl() const;
1688
1689  /// If this is a pointer or reference to a RecordType, return the
1690  /// CXXRecordDecl that that type refers to.
1691  ///
1692  /// If this is not a pointer or reference, or the type being pointed to does
1693  /// not refer to a CXXRecordDecl, returns NULL.
1694  const CXXRecordDecl *getPointeeCXXRecordDecl() const;
1695
1696  /// \brief Get the AutoType whose type will be deduced for a variable with
1697  /// an initializer of this type. This looks through declarators like pointer
1698  /// types, but not through decltype or typedefs.
1699  AutoType *getContainedAutoType() const;
1700
1701  /// Member-template getAs<specific type>'.  Look through sugar for
1702  /// an instance of \<specific type>.   This scheme will eventually
1703  /// replace the specific getAsXXXX methods above.
1704  ///
1705  /// There are some specializations of this member template listed
1706  /// immediately following this class.
1707  template <typename T> const T *getAs() const;
1708
1709  /// A variant of getAs<> for array types which silently discards
1710  /// qualifiers from the outermost type.
1711  const ArrayType *getAsArrayTypeUnsafe() const;
1712
1713  /// Member-template castAs<specific type>.  Look through sugar for
1714  /// the underlying instance of \<specific type>.
1715  ///
1716  /// This method has the same relationship to getAs<T> as cast<T> has
1717  /// to dyn_cast<T>; which is to say, the underlying type *must*
1718  /// have the intended type, and this method will never return null.
1719  template <typename T> const T *castAs() const;
1720
1721  /// A variant of castAs<> for array type which silently discards
1722  /// qualifiers from the outermost type.
1723  const ArrayType *castAsArrayTypeUnsafe() const;
1724
1725  /// getBaseElementTypeUnsafe - Get the base element type of this
1726  /// type, potentially discarding type qualifiers.  This method
1727  /// should never be used when type qualifiers are meaningful.
1728  const Type *getBaseElementTypeUnsafe() const;
1729
1730  /// getArrayElementTypeNoTypeQual - If this is an array type, return the
1731  /// element type of the array, potentially with type qualifiers missing.
1732  /// This method should never be used when type qualifiers are meaningful.
1733  const Type *getArrayElementTypeNoTypeQual() const;
1734
1735  /// getPointeeType - If this is a pointer, ObjC object pointer, or block
1736  /// pointer, this returns the respective pointee.
1737  QualType getPointeeType() const;
1738
1739  /// getUnqualifiedDesugaredType() - Return the specified type with
1740  /// any "sugar" removed from the type, removing any typedefs,
1741  /// typeofs, etc., as well as any qualifiers.
1742  const Type *getUnqualifiedDesugaredType() const;
1743
1744  /// More type predicates useful for type checking/promotion
1745  bool isPromotableIntegerType() const; // C99 6.3.1.1p2
1746
1747  /// isSignedIntegerType - Return true if this is an integer type that is
1748  /// signed, according to C99 6.2.5p4 [char, signed char, short, int, long..],
1749  /// or an enum decl which has a signed representation.
1750  bool isSignedIntegerType() const;
1751
1752  /// isUnsignedIntegerType - Return true if this is an integer type that is
1753  /// unsigned, according to C99 6.2.5p6 [which returns true for _Bool],
1754  /// or an enum decl which has an unsigned representation.
1755  bool isUnsignedIntegerType() const;
1756
1757  /// Determines whether this is an integer type that is signed or an
1758  /// enumeration types whose underlying type is a signed integer type.
1759  bool isSignedIntegerOrEnumerationType() const;
1760
1761  /// Determines whether this is an integer type that is unsigned or an
1762  /// enumeration types whose underlying type is a unsigned integer type.
1763  bool isUnsignedIntegerOrEnumerationType() const;
1764
1765  /// isConstantSizeType - Return true if this is not a variable sized type,
1766  /// according to the rules of C99 6.7.5p3.  It is not legal to call this on
1767  /// incomplete types.
1768  bool isConstantSizeType() const;
1769
1770  /// isSpecifierType - Returns true if this type can be represented by some
1771  /// set of type specifiers.
1772  bool isSpecifierType() const;
1773
1774  /// \brief Determine the linkage of this type.
1775  Linkage getLinkage() const;
1776
1777  /// \brief Determine the visibility of this type.
1778  Visibility getVisibility() const {
1779    return getLinkageAndVisibility().getVisibility();
1780  }
1781
1782  /// \brief Return true if the visibility was explicitly set is the code.
1783  bool isVisibilityExplicit() const {
1784    return getLinkageAndVisibility().isVisibilityExplicit();
1785  }
1786
1787  /// \brief Determine the linkage and visibility of this type.
1788  LinkageInfo getLinkageAndVisibility() const;
1789
1790  /// \brief True if the computed linkage is valid. Used for consistency
1791  /// checking. Should always return true.
1792  bool isLinkageValid() const;
1793
1794  const char *getTypeClassName() const;
1795
1796  QualType getCanonicalTypeInternal() const {
1797    return CanonicalType;
1798  }
1799  CanQualType getCanonicalTypeUnqualified() const; // in CanonicalType.h
1800  void dump() const;
1801
1802  friend class ASTReader;
1803  friend class ASTWriter;
1804};
1805
1806/// \brief This will check for a TypedefType by removing any existing sugar
1807/// until it reaches a TypedefType or a non-sugared type.
1808template <> const TypedefType *Type::getAs() const;
1809
1810/// \brief This will check for a TemplateSpecializationType by removing any
1811/// existing sugar until it reaches a TemplateSpecializationType or a
1812/// non-sugared type.
1813template <> const TemplateSpecializationType *Type::getAs() const;
1814
1815/// \brief This will check for an AttributedType by removing any existing sugar
1816/// until it reaches an AttributedType or a non-sugared type.
1817template <> const AttributedType *Type::getAs() const;
1818
1819// We can do canonical leaf types faster, because we don't have to
1820// worry about preserving child type decoration.
1821#define TYPE(Class, Base)
1822#define LEAF_TYPE(Class) \
1823template <> inline const Class##Type *Type::getAs() const { \
1824  return dyn_cast<Class##Type>(CanonicalType); \
1825} \
1826template <> inline const Class##Type *Type::castAs() const { \
1827  return cast<Class##Type>(CanonicalType); \
1828}
1829#include "clang/AST/TypeNodes.def"
1830
1831
1832/// BuiltinType - This class is used for builtin types like 'int'.  Builtin
1833/// types are always canonical and have a literal name field.
1834class BuiltinType : public Type {
1835public:
1836  enum Kind {
1837#define BUILTIN_TYPE(Id, SingletonId) Id,
1838#define LAST_BUILTIN_TYPE(Id) LastKind = Id
1839#include "clang/AST/BuiltinTypes.def"
1840  };
1841
1842public:
1843  BuiltinType(Kind K)
1844    : Type(Builtin, QualType(), /*Dependent=*/(K == Dependent),
1845           /*InstantiationDependent=*/(K == Dependent),
1846           /*VariablyModified=*/false,
1847           /*Unexpanded paramter pack=*/false) {
1848    BuiltinTypeBits.Kind = K;
1849  }
1850
1851  Kind getKind() const { return static_cast<Kind>(BuiltinTypeBits.Kind); }
1852  StringRef getName(const PrintingPolicy &Policy) const;
1853  const char *getNameAsCString(const PrintingPolicy &Policy) const {
1854    // The StringRef is null-terminated.
1855    StringRef str = getName(Policy);
1856    assert(!str.empty() && str.data()[str.size()] == '\0');
1857    return str.data();
1858  }
1859
1860  bool isSugared() const { return false; }
1861  QualType desugar() const { return QualType(this, 0); }
1862
1863  bool isInteger() const {
1864    return getKind() >= Bool && getKind() <= Int128;
1865  }
1866
1867  bool isSignedInteger() const {
1868    return getKind() >= Char_S && getKind() <= Int128;
1869  }
1870
1871  bool isUnsignedInteger() const {
1872    return getKind() >= Bool && getKind() <= UInt128;
1873  }
1874
1875  bool isFloatingPoint() const {
1876    return getKind() >= Half && getKind() <= LongDouble;
1877  }
1878
1879  /// Determines whether the given kind corresponds to a placeholder type.
1880  static bool isPlaceholderTypeKind(Kind K) {
1881    return K >= Overload;
1882  }
1883
1884  /// Determines whether this type is a placeholder type, i.e. a type
1885  /// which cannot appear in arbitrary positions in a fully-formed
1886  /// expression.
1887  bool isPlaceholderType() const {
1888    return isPlaceholderTypeKind(getKind());
1889  }
1890
1891  /// Determines whether this type is a placeholder type other than
1892  /// Overload.  Most placeholder types require only syntactic
1893  /// information about their context in order to be resolved (e.g.
1894  /// whether it is a call expression), which means they can (and
1895  /// should) be resolved in an earlier "phase" of analysis.
1896  /// Overload expressions sometimes pick up further information
1897  /// from their context, like whether the context expects a
1898  /// specific function-pointer type, and so frequently need
1899  /// special treatment.
1900  bool isNonOverloadPlaceholderType() const {
1901    return getKind() > Overload;
1902  }
1903
1904  static bool classof(const Type *T) { return T->getTypeClass() == Builtin; }
1905};
1906
1907/// ComplexType - C99 6.2.5p11 - Complex values.  This supports the C99 complex
1908/// types (_Complex float etc) as well as the GCC integer complex extensions.
1909///
1910class ComplexType : public Type, public llvm::FoldingSetNode {
1911  QualType ElementType;
1912  ComplexType(QualType Element, QualType CanonicalPtr) :
1913    Type(Complex, CanonicalPtr, Element->isDependentType(),
1914         Element->isInstantiationDependentType(),
1915         Element->isVariablyModifiedType(),
1916         Element->containsUnexpandedParameterPack()),
1917    ElementType(Element) {
1918  }
1919  friend class ASTContext;  // ASTContext creates these.
1920
1921public:
1922  QualType getElementType() const { return ElementType; }
1923
1924  bool isSugared() const { return false; }
1925  QualType desugar() const { return QualType(this, 0); }
1926
1927  void Profile(llvm::FoldingSetNodeID &ID) {
1928    Profile(ID, getElementType());
1929  }
1930  static void Profile(llvm::FoldingSetNodeID &ID, QualType Element) {
1931    ID.AddPointer(Element.getAsOpaquePtr());
1932  }
1933
1934  static bool classof(const Type *T) { return T->getTypeClass() == Complex; }
1935};
1936
1937/// ParenType - Sugar for parentheses used when specifying types.
1938///
1939class ParenType : public Type, public llvm::FoldingSetNode {
1940  QualType Inner;
1941
1942  ParenType(QualType InnerType, QualType CanonType) :
1943    Type(Paren, CanonType, InnerType->isDependentType(),
1944         InnerType->isInstantiationDependentType(),
1945         InnerType->isVariablyModifiedType(),
1946         InnerType->containsUnexpandedParameterPack()),
1947    Inner(InnerType) {
1948  }
1949  friend class ASTContext;  // ASTContext creates these.
1950
1951public:
1952
1953  QualType getInnerType() const { return Inner; }
1954
1955  bool isSugared() const { return true; }
1956  QualType desugar() const { return getInnerType(); }
1957
1958  void Profile(llvm::FoldingSetNodeID &ID) {
1959    Profile(ID, getInnerType());
1960  }
1961  static void Profile(llvm::FoldingSetNodeID &ID, QualType Inner) {
1962    Inner.Profile(ID);
1963  }
1964
1965  static bool classof(const Type *T) { return T->getTypeClass() == Paren; }
1966};
1967
1968/// PointerType - C99 6.7.5.1 - Pointer Declarators.
1969///
1970class PointerType : public Type, public llvm::FoldingSetNode {
1971  QualType PointeeType;
1972
1973  PointerType(QualType Pointee, QualType CanonicalPtr) :
1974    Type(Pointer, CanonicalPtr, Pointee->isDependentType(),
1975         Pointee->isInstantiationDependentType(),
1976         Pointee->isVariablyModifiedType(),
1977         Pointee->containsUnexpandedParameterPack()),
1978    PointeeType(Pointee) {
1979  }
1980  friend class ASTContext;  // ASTContext creates these.
1981
1982public:
1983
1984  QualType getPointeeType() const { return PointeeType; }
1985
1986  bool isSugared() const { return false; }
1987  QualType desugar() const { return QualType(this, 0); }
1988
1989  void Profile(llvm::FoldingSetNodeID &ID) {
1990    Profile(ID, getPointeeType());
1991  }
1992  static void Profile(llvm::FoldingSetNodeID &ID, QualType Pointee) {
1993    ID.AddPointer(Pointee.getAsOpaquePtr());
1994  }
1995
1996  static bool classof(const Type *T) { return T->getTypeClass() == Pointer; }
1997};
1998
1999/// \brief Represents a type which was implicitly adjusted by the semantic
2000/// engine for arbitrary reasons.  For example, array and function types can
2001/// decay, and function types can have their calling conventions adjusted.
2002class AdjustedType : public Type, public llvm::FoldingSetNode {
2003  QualType OriginalTy;
2004  QualType AdjustedTy;
2005
2006protected:
2007  AdjustedType(TypeClass TC, QualType OriginalTy, QualType AdjustedTy,
2008               QualType CanonicalPtr)
2009      : Type(TC, CanonicalPtr, OriginalTy->isDependentType(),
2010             OriginalTy->isInstantiationDependentType(),
2011             OriginalTy->isVariablyModifiedType(),
2012             OriginalTy->containsUnexpandedParameterPack()),
2013        OriginalTy(OriginalTy), AdjustedTy(AdjustedTy) {}
2014
2015  friend class ASTContext;  // ASTContext creates these.
2016
2017public:
2018  QualType getOriginalType() const { return OriginalTy; }
2019  QualType getAdjustedType() const { return AdjustedTy; }
2020
2021  bool isSugared() const { return true; }
2022  QualType desugar() const { return AdjustedTy; }
2023
2024  void Profile(llvm::FoldingSetNodeID &ID) {
2025    Profile(ID, OriginalTy, AdjustedTy);
2026  }
2027  static void Profile(llvm::FoldingSetNodeID &ID, QualType Orig, QualType New) {
2028    ID.AddPointer(Orig.getAsOpaquePtr());
2029    ID.AddPointer(New.getAsOpaquePtr());
2030  }
2031
2032  static bool classof(const Type *T) {
2033    return T->getTypeClass() == Adjusted || T->getTypeClass() == Decayed;
2034  }
2035};
2036
2037/// \brief Represents a pointer type decayed from an array or function type.
2038class DecayedType : public AdjustedType {
2039
2040  DecayedType(QualType OriginalType, QualType DecayedPtr, QualType CanonicalPtr)
2041      : AdjustedType(Decayed, OriginalType, DecayedPtr, CanonicalPtr) {
2042    assert(isa<PointerType>(getAdjustedType()));
2043  }
2044
2045  friend class ASTContext;  // ASTContext creates these.
2046
2047public:
2048  QualType getDecayedType() const { return getAdjustedType(); }
2049
2050  QualType getPointeeType() const {
2051    return cast<PointerType>(getDecayedType())->getPointeeType();
2052  }
2053
2054  static bool classof(const Type *T) { return T->getTypeClass() == Decayed; }
2055};
2056
2057/// BlockPointerType - pointer to a block type.
2058/// This type is to represent types syntactically represented as
2059/// "void (^)(int)", etc. Pointee is required to always be a function type.
2060///
2061class BlockPointerType : public Type, public llvm::FoldingSetNode {
2062  QualType PointeeType;  // Block is some kind of pointer type
2063  BlockPointerType(QualType Pointee, QualType CanonicalCls) :
2064    Type(BlockPointer, CanonicalCls, Pointee->isDependentType(),
2065         Pointee->isInstantiationDependentType(),
2066         Pointee->isVariablyModifiedType(),
2067         Pointee->containsUnexpandedParameterPack()),
2068    PointeeType(Pointee) {
2069  }
2070  friend class ASTContext;  // ASTContext creates these.
2071
2072public:
2073
2074  // Get the pointee type. Pointee is required to always be a function type.
2075  QualType getPointeeType() const { return PointeeType; }
2076
2077  bool isSugared() const { return false; }
2078  QualType desugar() const { return QualType(this, 0); }
2079
2080  void Profile(llvm::FoldingSetNodeID &ID) {
2081      Profile(ID, getPointeeType());
2082  }
2083  static void Profile(llvm::FoldingSetNodeID &ID, QualType Pointee) {
2084      ID.AddPointer(Pointee.getAsOpaquePtr());
2085  }
2086
2087  static bool classof(const Type *T) {
2088    return T->getTypeClass() == BlockPointer;
2089  }
2090};
2091
2092/// ReferenceType - Base for LValueReferenceType and RValueReferenceType
2093///
2094class ReferenceType : public Type, public llvm::FoldingSetNode {
2095  QualType PointeeType;
2096
2097protected:
2098  ReferenceType(TypeClass tc, QualType Referencee, QualType CanonicalRef,
2099                bool SpelledAsLValue) :
2100    Type(tc, CanonicalRef, Referencee->isDependentType(),
2101         Referencee->isInstantiationDependentType(),
2102         Referencee->isVariablyModifiedType(),
2103         Referencee->containsUnexpandedParameterPack()),
2104    PointeeType(Referencee)
2105  {
2106    ReferenceTypeBits.SpelledAsLValue = SpelledAsLValue;
2107    ReferenceTypeBits.InnerRef = Referencee->isReferenceType();
2108  }
2109
2110public:
2111  bool isSpelledAsLValue() const { return ReferenceTypeBits.SpelledAsLValue; }
2112  bool isInnerRef() const { return ReferenceTypeBits.InnerRef; }
2113
2114  QualType getPointeeTypeAsWritten() const { return PointeeType; }
2115  QualType getPointeeType() const {
2116    // FIXME: this might strip inner qualifiers; okay?
2117    const ReferenceType *T = this;
2118    while (T->isInnerRef())
2119      T = T->PointeeType->castAs<ReferenceType>();
2120    return T->PointeeType;
2121  }
2122
2123  void Profile(llvm::FoldingSetNodeID &ID) {
2124    Profile(ID, PointeeType, isSpelledAsLValue());
2125  }
2126  static void Profile(llvm::FoldingSetNodeID &ID,
2127                      QualType Referencee,
2128                      bool SpelledAsLValue) {
2129    ID.AddPointer(Referencee.getAsOpaquePtr());
2130    ID.AddBoolean(SpelledAsLValue);
2131  }
2132
2133  static bool classof(const Type *T) {
2134    return T->getTypeClass() == LValueReference ||
2135           T->getTypeClass() == RValueReference;
2136  }
2137};
2138
2139/// LValueReferenceType - C++ [dcl.ref] - Lvalue reference
2140///
2141class LValueReferenceType : public ReferenceType {
2142  LValueReferenceType(QualType Referencee, QualType CanonicalRef,
2143                      bool SpelledAsLValue) :
2144    ReferenceType(LValueReference, Referencee, CanonicalRef, SpelledAsLValue)
2145  {}
2146  friend class ASTContext; // ASTContext creates these
2147public:
2148  bool isSugared() const { return false; }
2149  QualType desugar() const { return QualType(this, 0); }
2150
2151  static bool classof(const Type *T) {
2152    return T->getTypeClass() == LValueReference;
2153  }
2154};
2155
2156/// RValueReferenceType - C++0x [dcl.ref] - Rvalue reference
2157///
2158class RValueReferenceType : public ReferenceType {
2159  RValueReferenceType(QualType Referencee, QualType CanonicalRef) :
2160    ReferenceType(RValueReference, Referencee, CanonicalRef, false) {
2161  }
2162  friend class ASTContext; // ASTContext creates these
2163public:
2164  bool isSugared() const { return false; }
2165  QualType desugar() const { return QualType(this, 0); }
2166
2167  static bool classof(const Type *T) {
2168    return T->getTypeClass() == RValueReference;
2169  }
2170};
2171
2172/// MemberPointerType - C++ 8.3.3 - Pointers to members
2173///
2174class MemberPointerType : public Type, public llvm::FoldingSetNode {
2175  QualType PointeeType;
2176  /// The class of which the pointee is a member. Must ultimately be a
2177  /// RecordType, but could be a typedef or a template parameter too.
2178  const Type *Class;
2179
2180  MemberPointerType(QualType Pointee, const Type *Cls, QualType CanonicalPtr) :
2181    Type(MemberPointer, CanonicalPtr,
2182         Cls->isDependentType() || Pointee->isDependentType(),
2183         (Cls->isInstantiationDependentType() ||
2184          Pointee->isInstantiationDependentType()),
2185         Pointee->isVariablyModifiedType(),
2186         (Cls->containsUnexpandedParameterPack() ||
2187          Pointee->containsUnexpandedParameterPack())),
2188    PointeeType(Pointee), Class(Cls) {
2189  }
2190  friend class ASTContext; // ASTContext creates these.
2191
2192public:
2193  QualType getPointeeType() const { return PointeeType; }
2194
2195  /// Returns true if the member type (i.e. the pointee type) is a
2196  /// function type rather than a data-member type.
2197  bool isMemberFunctionPointer() const {
2198    return PointeeType->isFunctionProtoType();
2199  }
2200
2201  /// Returns true if the member type (i.e. the pointee type) is a
2202  /// data type rather than a function type.
2203  bool isMemberDataPointer() const {
2204    return !PointeeType->isFunctionProtoType();
2205  }
2206
2207  const Type *getClass() const { return Class; }
2208  CXXRecordDecl *getMostRecentCXXRecordDecl() const;
2209
2210  bool isSugared() const { return false; }
2211  QualType desugar() const { return QualType(this, 0); }
2212
2213  void Profile(llvm::FoldingSetNodeID &ID) {
2214    Profile(ID, getPointeeType(), getClass());
2215  }
2216  static void Profile(llvm::FoldingSetNodeID &ID, QualType Pointee,
2217                      const Type *Class) {
2218    ID.AddPointer(Pointee.getAsOpaquePtr());
2219    ID.AddPointer(Class);
2220  }
2221
2222  static bool classof(const Type *T) {
2223    return T->getTypeClass() == MemberPointer;
2224  }
2225};
2226
2227/// ArrayType - C99 6.7.5.2 - Array Declarators.
2228///
2229class ArrayType : public Type, public llvm::FoldingSetNode {
2230public:
2231  /// ArraySizeModifier - Capture whether this is a normal array (e.g. int X[4])
2232  /// an array with a static size (e.g. int X[static 4]), or an array
2233  /// with a star size (e.g. int X[*]).
2234  /// 'static' is only allowed on function parameters.
2235  enum ArraySizeModifier {
2236    Normal, Static, Star
2237  };
2238private:
2239  /// ElementType - The element type of the array.
2240  QualType ElementType;
2241
2242protected:
2243  // C++ [temp.dep.type]p1:
2244  //   A type is dependent if it is...
2245  //     - an array type constructed from any dependent type or whose
2246  //       size is specified by a constant expression that is
2247  //       value-dependent,
2248  ArrayType(TypeClass tc, QualType et, QualType can,
2249            ArraySizeModifier sm, unsigned tq,
2250            bool ContainsUnexpandedParameterPack)
2251    : Type(tc, can, et->isDependentType() || tc == DependentSizedArray,
2252           et->isInstantiationDependentType() || tc == DependentSizedArray,
2253           (tc == VariableArray || et->isVariablyModifiedType()),
2254           ContainsUnexpandedParameterPack),
2255      ElementType(et) {
2256    ArrayTypeBits.IndexTypeQuals = tq;
2257    ArrayTypeBits.SizeModifier = sm;
2258  }
2259
2260  friend class ASTContext;  // ASTContext creates these.
2261
2262public:
2263  QualType getElementType() const { return ElementType; }
2264  ArraySizeModifier getSizeModifier() const {
2265    return ArraySizeModifier(ArrayTypeBits.SizeModifier);
2266  }
2267  Qualifiers getIndexTypeQualifiers() const {
2268    return Qualifiers::fromCVRMask(getIndexTypeCVRQualifiers());
2269  }
2270  unsigned getIndexTypeCVRQualifiers() const {
2271    return ArrayTypeBits.IndexTypeQuals;
2272  }
2273
2274  static bool classof(const Type *T) {
2275    return T->getTypeClass() == ConstantArray ||
2276           T->getTypeClass() == VariableArray ||
2277           T->getTypeClass() == IncompleteArray ||
2278           T->getTypeClass() == DependentSizedArray;
2279  }
2280};
2281
2282/// ConstantArrayType - This class represents the canonical version of
2283/// C arrays with a specified constant size.  For example, the canonical
2284/// type for 'int A[4 + 4*100]' is a ConstantArrayType where the element
2285/// type is 'int' and the size is 404.
2286class ConstantArrayType : public ArrayType {
2287  llvm::APInt Size; // Allows us to unique the type.
2288
2289  ConstantArrayType(QualType et, QualType can, const llvm::APInt &size,
2290                    ArraySizeModifier sm, unsigned tq)
2291    : ArrayType(ConstantArray, et, can, sm, tq,
2292                et->containsUnexpandedParameterPack()),
2293      Size(size) {}
2294protected:
2295  ConstantArrayType(TypeClass tc, QualType et, QualType can,
2296                    const llvm::APInt &size, ArraySizeModifier sm, unsigned tq)
2297    : ArrayType(tc, et, can, sm, tq, et->containsUnexpandedParameterPack()),
2298      Size(size) {}
2299  friend class ASTContext;  // ASTContext creates these.
2300public:
2301  const llvm::APInt &getSize() const { return Size; }
2302  bool isSugared() const { return false; }
2303  QualType desugar() const { return QualType(this, 0); }
2304
2305
2306  /// \brief Determine the number of bits required to address a member of
2307  // an array with the given element type and number of elements.
2308  static unsigned getNumAddressingBits(ASTContext &Context,
2309                                       QualType ElementType,
2310                                       const llvm::APInt &NumElements);
2311
2312  /// \brief Determine the maximum number of active bits that an array's size
2313  /// can require, which limits the maximum size of the array.
2314  static unsigned getMaxSizeBits(ASTContext &Context);
2315
2316  void Profile(llvm::FoldingSetNodeID &ID) {
2317    Profile(ID, getElementType(), getSize(),
2318            getSizeModifier(), getIndexTypeCVRQualifiers());
2319  }
2320  static void Profile(llvm::FoldingSetNodeID &ID, QualType ET,
2321                      const llvm::APInt &ArraySize, ArraySizeModifier SizeMod,
2322                      unsigned TypeQuals) {
2323    ID.AddPointer(ET.getAsOpaquePtr());
2324    ID.AddInteger(ArraySize.getZExtValue());
2325    ID.AddInteger(SizeMod);
2326    ID.AddInteger(TypeQuals);
2327  }
2328  static bool classof(const Type *T) {
2329    return T->getTypeClass() == ConstantArray;
2330  }
2331};
2332
2333/// IncompleteArrayType - This class represents C arrays with an unspecified
2334/// size.  For example 'int A[]' has an IncompleteArrayType where the element
2335/// type is 'int' and the size is unspecified.
2336class IncompleteArrayType : public ArrayType {
2337
2338  IncompleteArrayType(QualType et, QualType can,
2339                      ArraySizeModifier sm, unsigned tq)
2340    : ArrayType(IncompleteArray, et, can, sm, tq,
2341                et->containsUnexpandedParameterPack()) {}
2342  friend class ASTContext;  // ASTContext creates these.
2343public:
2344  bool isSugared() const { return false; }
2345  QualType desugar() const { return QualType(this, 0); }
2346
2347  static bool classof(const Type *T) {
2348    return T->getTypeClass() == IncompleteArray;
2349  }
2350
2351  friend class StmtIteratorBase;
2352
2353  void Profile(llvm::FoldingSetNodeID &ID) {
2354    Profile(ID, getElementType(), getSizeModifier(),
2355            getIndexTypeCVRQualifiers());
2356  }
2357
2358  static void Profile(llvm::FoldingSetNodeID &ID, QualType ET,
2359                      ArraySizeModifier SizeMod, unsigned TypeQuals) {
2360    ID.AddPointer(ET.getAsOpaquePtr());
2361    ID.AddInteger(SizeMod);
2362    ID.AddInteger(TypeQuals);
2363  }
2364};
2365
2366/// VariableArrayType - This class represents C arrays with a specified size
2367/// which is not an integer-constant-expression.  For example, 'int s[x+foo()]'.
2368/// Since the size expression is an arbitrary expression, we store it as such.
2369///
2370/// Note: VariableArrayType's aren't uniqued (since the expressions aren't) and
2371/// should not be: two lexically equivalent variable array types could mean
2372/// different things, for example, these variables do not have the same type
2373/// dynamically:
2374///
2375/// void foo(int x) {
2376///   int Y[x];
2377///   ++x;
2378///   int Z[x];
2379/// }
2380///
2381class VariableArrayType : public ArrayType {
2382  /// SizeExpr - An assignment expression. VLA's are only permitted within
2383  /// a function block.
2384  Stmt *SizeExpr;
2385  /// Brackets - The left and right array brackets.
2386  SourceRange Brackets;
2387
2388  VariableArrayType(QualType et, QualType can, Expr *e,
2389                    ArraySizeModifier sm, unsigned tq,
2390                    SourceRange brackets)
2391    : ArrayType(VariableArray, et, can, sm, tq,
2392                et->containsUnexpandedParameterPack()),
2393      SizeExpr((Stmt*) e), Brackets(brackets) {}
2394  friend class ASTContext;  // ASTContext creates these.
2395
2396public:
2397  Expr *getSizeExpr() const {
2398    // We use C-style casts instead of cast<> here because we do not wish
2399    // to have a dependency of Type.h on Stmt.h/Expr.h.
2400    return (Expr*) SizeExpr;
2401  }
2402  SourceRange getBracketsRange() const { return Brackets; }
2403  SourceLocation getLBracketLoc() const { return Brackets.getBegin(); }
2404  SourceLocation getRBracketLoc() const { return Brackets.getEnd(); }
2405
2406  bool isSugared() const { return false; }
2407  QualType desugar() const { return QualType(this, 0); }
2408
2409  static bool classof(const Type *T) {
2410    return T->getTypeClass() == VariableArray;
2411  }
2412
2413  friend class StmtIteratorBase;
2414
2415  void Profile(llvm::FoldingSetNodeID &ID) {
2416    llvm_unreachable("Cannot unique VariableArrayTypes.");
2417  }
2418};
2419
2420/// DependentSizedArrayType - This type represents an array type in
2421/// C++ whose size is a value-dependent expression. For example:
2422///
2423/// \code
2424/// template<typename T, int Size>
2425/// class array {
2426///   T data[Size];
2427/// };
2428/// \endcode
2429///
2430/// For these types, we won't actually know what the array bound is
2431/// until template instantiation occurs, at which point this will
2432/// become either a ConstantArrayType or a VariableArrayType.
2433class DependentSizedArrayType : public ArrayType {
2434  const ASTContext &Context;
2435
2436  /// \brief An assignment expression that will instantiate to the
2437  /// size of the array.
2438  ///
2439  /// The expression itself might be NULL, in which case the array
2440  /// type will have its size deduced from an initializer.
2441  Stmt *SizeExpr;
2442
2443  /// Brackets - The left and right array brackets.
2444  SourceRange Brackets;
2445
2446  DependentSizedArrayType(const ASTContext &Context, QualType et, QualType can,
2447                          Expr *e, ArraySizeModifier sm, unsigned tq,
2448                          SourceRange brackets);
2449
2450  friend class ASTContext;  // ASTContext creates these.
2451
2452public:
2453  Expr *getSizeExpr() const {
2454    // We use C-style casts instead of cast<> here because we do not wish
2455    // to have a dependency of Type.h on Stmt.h/Expr.h.
2456    return (Expr*) SizeExpr;
2457  }
2458  SourceRange getBracketsRange() const { return Brackets; }
2459  SourceLocation getLBracketLoc() const { return Brackets.getBegin(); }
2460  SourceLocation getRBracketLoc() const { return Brackets.getEnd(); }
2461
2462  bool isSugared() const { return false; }
2463  QualType desugar() const { return QualType(this, 0); }
2464
2465  static bool classof(const Type *T) {
2466    return T->getTypeClass() == DependentSizedArray;
2467  }
2468
2469  friend class StmtIteratorBase;
2470
2471
2472  void Profile(llvm::FoldingSetNodeID &ID) {
2473    Profile(ID, Context, getElementType(),
2474            getSizeModifier(), getIndexTypeCVRQualifiers(), getSizeExpr());
2475  }
2476
2477  static void Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Context,
2478                      QualType ET, ArraySizeModifier SizeMod,
2479                      unsigned TypeQuals, Expr *E);
2480};
2481
2482/// DependentSizedExtVectorType - This type represent an extended vector type
2483/// where either the type or size is dependent. For example:
2484/// @code
2485/// template<typename T, int Size>
2486/// class vector {
2487///   typedef T __attribute__((ext_vector_type(Size))) type;
2488/// }
2489/// @endcode
2490class DependentSizedExtVectorType : public Type, public llvm::FoldingSetNode {
2491  const ASTContext &Context;
2492  Expr *SizeExpr;
2493  /// ElementType - The element type of the array.
2494  QualType ElementType;
2495  SourceLocation loc;
2496
2497  DependentSizedExtVectorType(const ASTContext &Context, QualType ElementType,
2498                              QualType can, Expr *SizeExpr, SourceLocation loc);
2499
2500  friend class ASTContext;
2501
2502public:
2503  Expr *getSizeExpr() const { return SizeExpr; }
2504  QualType getElementType() const { return ElementType; }
2505  SourceLocation getAttributeLoc() const { return loc; }
2506
2507  bool isSugared() const { return false; }
2508  QualType desugar() const { return QualType(this, 0); }
2509
2510  static bool classof(const Type *T) {
2511    return T->getTypeClass() == DependentSizedExtVector;
2512  }
2513
2514  void Profile(llvm::FoldingSetNodeID &ID) {
2515    Profile(ID, Context, getElementType(), getSizeExpr());
2516  }
2517
2518  static void Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Context,
2519                      QualType ElementType, Expr *SizeExpr);
2520};
2521
2522
2523/// VectorType - GCC generic vector type. This type is created using
2524/// __attribute__((vector_size(n)), where "n" specifies the vector size in
2525/// bytes; or from an Altivec __vector or vector declaration.
2526/// Since the constructor takes the number of vector elements, the
2527/// client is responsible for converting the size into the number of elements.
2528class VectorType : public Type, public llvm::FoldingSetNode {
2529public:
2530  enum VectorKind {
2531    GenericVector,  // not a target-specific vector type
2532    AltiVecVector,  // is AltiVec vector
2533    AltiVecPixel,   // is AltiVec 'vector Pixel'
2534    AltiVecBool,    // is AltiVec 'vector bool ...'
2535    NeonVector,     // is ARM Neon vector
2536    NeonPolyVector  // is ARM Neon polynomial vector
2537  };
2538protected:
2539  /// ElementType - The element type of the vector.
2540  QualType ElementType;
2541
2542  VectorType(QualType vecType, unsigned nElements, QualType canonType,
2543             VectorKind vecKind);
2544
2545  VectorType(TypeClass tc, QualType vecType, unsigned nElements,
2546             QualType canonType, VectorKind vecKind);
2547
2548  friend class ASTContext;  // ASTContext creates these.
2549
2550public:
2551
2552  QualType getElementType() const { return ElementType; }
2553  unsigned getNumElements() const { return VectorTypeBits.NumElements; }
2554  static bool isVectorSizeTooLarge(unsigned NumElements) {
2555    return NumElements > VectorTypeBitfields::MaxNumElements;
2556  }
2557
2558  bool isSugared() const { return false; }
2559  QualType desugar() const { return QualType(this, 0); }
2560
2561  VectorKind getVectorKind() const {
2562    return VectorKind(VectorTypeBits.VecKind);
2563  }
2564
2565  void Profile(llvm::FoldingSetNodeID &ID) {
2566    Profile(ID, getElementType(), getNumElements(),
2567            getTypeClass(), getVectorKind());
2568  }
2569  static void Profile(llvm::FoldingSetNodeID &ID, QualType ElementType,
2570                      unsigned NumElements, TypeClass TypeClass,
2571                      VectorKind VecKind) {
2572    ID.AddPointer(ElementType.getAsOpaquePtr());
2573    ID.AddInteger(NumElements);
2574    ID.AddInteger(TypeClass);
2575    ID.AddInteger(VecKind);
2576  }
2577
2578  static bool classof(const Type *T) {
2579    return T->getTypeClass() == Vector || T->getTypeClass() == ExtVector;
2580  }
2581};
2582
2583/// ExtVectorType - Extended vector type. This type is created using
2584/// __attribute__((ext_vector_type(n)), where "n" is the number of elements.
2585/// Unlike vector_size, ext_vector_type is only allowed on typedef's. This
2586/// class enables syntactic extensions, like Vector Components for accessing
2587/// points, colors, and textures (modeled after OpenGL Shading Language).
2588class ExtVectorType : public VectorType {
2589  ExtVectorType(QualType vecType, unsigned nElements, QualType canonType) :
2590    VectorType(ExtVector, vecType, nElements, canonType, GenericVector) {}
2591  friend class ASTContext;  // ASTContext creates these.
2592public:
2593  static int getPointAccessorIdx(char c) {
2594    switch (c) {
2595    default: return -1;
2596    case 'x': case 'r': return 0;
2597    case 'y': case 'g': return 1;
2598    case 'z': case 'b': return 2;
2599    case 'w': case 'a': return 3;
2600    }
2601  }
2602  static int getNumericAccessorIdx(char c) {
2603    switch (c) {
2604      default: return -1;
2605      case '0': return 0;
2606      case '1': return 1;
2607      case '2': return 2;
2608      case '3': return 3;
2609      case '4': return 4;
2610      case '5': return 5;
2611      case '6': return 6;
2612      case '7': return 7;
2613      case '8': return 8;
2614      case '9': return 9;
2615      case 'A':
2616      case 'a': return 10;
2617      case 'B':
2618      case 'b': return 11;
2619      case 'C':
2620      case 'c': return 12;
2621      case 'D':
2622      case 'd': return 13;
2623      case 'E':
2624      case 'e': return 14;
2625      case 'F':
2626      case 'f': return 15;
2627    }
2628  }
2629
2630  static int getAccessorIdx(char c) {
2631    if (int idx = getPointAccessorIdx(c)+1) return idx-1;
2632    return getNumericAccessorIdx(c);
2633  }
2634
2635  bool isAccessorWithinNumElements(char c) const {
2636    if (int idx = getAccessorIdx(c)+1)
2637      return unsigned(idx-1) < getNumElements();
2638    return false;
2639  }
2640  bool isSugared() const { return false; }
2641  QualType desugar() const { return QualType(this, 0); }
2642
2643  static bool classof(const Type *T) {
2644    return T->getTypeClass() == ExtVector;
2645  }
2646};
2647
2648/// FunctionType - C99 6.7.5.3 - Function Declarators.  This is the common base
2649/// class of FunctionNoProtoType and FunctionProtoType.
2650///
2651class FunctionType : public Type {
2652  // The type returned by the function.
2653  QualType ResultType;
2654
2655 public:
2656  /// ExtInfo - A class which abstracts out some details necessary for
2657  /// making a call.
2658  ///
2659  /// It is not actually used directly for storing this information in
2660  /// a FunctionType, although FunctionType does currently use the
2661  /// same bit-pattern.
2662  ///
2663  // If you add a field (say Foo), other than the obvious places (both,
2664  // constructors, compile failures), what you need to update is
2665  // * Operator==
2666  // * getFoo
2667  // * withFoo
2668  // * functionType. Add Foo, getFoo.
2669  // * ASTContext::getFooType
2670  // * ASTContext::mergeFunctionTypes
2671  // * FunctionNoProtoType::Profile
2672  // * FunctionProtoType::Profile
2673  // * TypePrinter::PrintFunctionProto
2674  // * AST read and write
2675  // * Codegen
2676  class ExtInfo {
2677    // Feel free to rearrange or add bits, but if you go over 9,
2678    // you'll need to adjust both the Bits field below and
2679    // Type::FunctionTypeBitfields.
2680
2681    //   |  CC  |noreturn|produces|regparm|
2682    //   |0 .. 3|   4    |    5   | 6 .. 8|
2683    //
2684    // regparm is either 0 (no regparm attribute) or the regparm value+1.
2685    enum { CallConvMask = 0xF };
2686    enum { NoReturnMask = 0x10 };
2687    enum { ProducesResultMask = 0x20 };
2688    enum { RegParmMask = ~(CallConvMask | NoReturnMask | ProducesResultMask),
2689           RegParmOffset = 6 }; // Assumed to be the last field
2690
2691    uint16_t Bits;
2692
2693    ExtInfo(unsigned Bits) : Bits(static_cast<uint16_t>(Bits)) {}
2694
2695    friend class FunctionType;
2696
2697   public:
2698    // Constructor with no defaults. Use this when you know that you
2699    // have all the elements (when reading an AST file for example).
2700    ExtInfo(bool noReturn, bool hasRegParm, unsigned regParm, CallingConv cc,
2701            bool producesResult) {
2702      assert((!hasRegParm || regParm < 7) && "Invalid regparm value");
2703      Bits = ((unsigned) cc) |
2704             (noReturn ? NoReturnMask : 0) |
2705             (producesResult ? ProducesResultMask : 0) |
2706             (hasRegParm ? ((regParm + 1) << RegParmOffset) : 0);
2707    }
2708
2709    // Constructor with all defaults. Use when for example creating a
2710    // function know to use defaults.
2711    ExtInfo() : Bits(CC_C) { }
2712
2713    // Constructor with just the calling convention, which is an important part
2714    // of the canonical type.
2715    ExtInfo(CallingConv CC) : Bits(CC) { }
2716
2717    bool getNoReturn() const { return Bits & NoReturnMask; }
2718    bool getProducesResult() const { return Bits & ProducesResultMask; }
2719    bool getHasRegParm() const { return (Bits >> RegParmOffset) != 0; }
2720    unsigned getRegParm() const {
2721      unsigned RegParm = Bits >> RegParmOffset;
2722      if (RegParm > 0)
2723        --RegParm;
2724      return RegParm;
2725    }
2726    CallingConv getCC() const { return CallingConv(Bits & CallConvMask); }
2727
2728    bool operator==(ExtInfo Other) const {
2729      return Bits == Other.Bits;
2730    }
2731    bool operator!=(ExtInfo Other) const {
2732      return Bits != Other.Bits;
2733    }
2734
2735    // Note that we don't have setters. That is by design, use
2736    // the following with methods instead of mutating these objects.
2737
2738    ExtInfo withNoReturn(bool noReturn) const {
2739      if (noReturn)
2740        return ExtInfo(Bits | NoReturnMask);
2741      else
2742        return ExtInfo(Bits & ~NoReturnMask);
2743    }
2744
2745    ExtInfo withProducesResult(bool producesResult) const {
2746      if (producesResult)
2747        return ExtInfo(Bits | ProducesResultMask);
2748      else
2749        return ExtInfo(Bits & ~ProducesResultMask);
2750    }
2751
2752    ExtInfo withRegParm(unsigned RegParm) const {
2753      assert(RegParm < 7 && "Invalid regparm value");
2754      return ExtInfo((Bits & ~RegParmMask) |
2755                     ((RegParm + 1) << RegParmOffset));
2756    }
2757
2758    ExtInfo withCallingConv(CallingConv cc) const {
2759      return ExtInfo((Bits & ~CallConvMask) | (unsigned) cc);
2760    }
2761
2762    void Profile(llvm::FoldingSetNodeID &ID) const {
2763      ID.AddInteger(Bits);
2764    }
2765  };
2766
2767protected:
2768  FunctionType(TypeClass tc, QualType res,
2769               unsigned typeQuals, QualType Canonical, bool Dependent,
2770               bool InstantiationDependent,
2771               bool VariablyModified, bool ContainsUnexpandedParameterPack,
2772               ExtInfo Info)
2773    : Type(tc, Canonical, Dependent, InstantiationDependent, VariablyModified,
2774           ContainsUnexpandedParameterPack),
2775      ResultType(res) {
2776    FunctionTypeBits.ExtInfo = Info.Bits;
2777    FunctionTypeBits.TypeQuals = typeQuals;
2778  }
2779  unsigned getTypeQuals() const { return FunctionTypeBits.TypeQuals; }
2780
2781public:
2782  QualType getReturnType() const { return ResultType; }
2783
2784  bool getHasRegParm() const { return getExtInfo().getHasRegParm(); }
2785  unsigned getRegParmType() const { return getExtInfo().getRegParm(); }
2786  /// \brief Determine whether this function type includes the GNU noreturn
2787  /// attribute. The C++11 [[noreturn]] attribute does not affect the function
2788  /// type.
2789  bool getNoReturnAttr() const { return getExtInfo().getNoReturn(); }
2790  CallingConv getCallConv() const { return getExtInfo().getCC(); }
2791  ExtInfo getExtInfo() const { return ExtInfo(FunctionTypeBits.ExtInfo); }
2792  bool isConst() const { return getTypeQuals() & Qualifiers::Const; }
2793  bool isVolatile() const { return getTypeQuals() & Qualifiers::Volatile; }
2794  bool isRestrict() const { return getTypeQuals() & Qualifiers::Restrict; }
2795
2796  /// \brief Determine the type of an expression that calls a function of
2797  /// this type.
2798  QualType getCallResultType(ASTContext &Context) const {
2799    return getReturnType().getNonLValueExprType(Context);
2800  }
2801
2802  static StringRef getNameForCallConv(CallingConv CC);
2803
2804  static bool classof(const Type *T) {
2805    return T->getTypeClass() == FunctionNoProto ||
2806           T->getTypeClass() == FunctionProto;
2807  }
2808};
2809
2810/// FunctionNoProtoType - Represents a K&R-style 'int foo()' function, which has
2811/// no information available about its arguments.
2812class FunctionNoProtoType : public FunctionType, public llvm::FoldingSetNode {
2813  FunctionNoProtoType(QualType Result, QualType Canonical, ExtInfo Info)
2814    : FunctionType(FunctionNoProto, Result, 0, Canonical,
2815                   /*Dependent=*/false, /*InstantiationDependent=*/false,
2816                   Result->isVariablyModifiedType(),
2817                   /*ContainsUnexpandedParameterPack=*/false, Info) {}
2818
2819  friend class ASTContext;  // ASTContext creates these.
2820
2821public:
2822  // No additional state past what FunctionType provides.
2823
2824  bool isSugared() const { return false; }
2825  QualType desugar() const { return QualType(this, 0); }
2826
2827  void Profile(llvm::FoldingSetNodeID &ID) {
2828    Profile(ID, getReturnType(), getExtInfo());
2829  }
2830  static void Profile(llvm::FoldingSetNodeID &ID, QualType ResultType,
2831                      ExtInfo Info) {
2832    Info.Profile(ID);
2833    ID.AddPointer(ResultType.getAsOpaquePtr());
2834  }
2835
2836  static bool classof(const Type *T) {
2837    return T->getTypeClass() == FunctionNoProto;
2838  }
2839};
2840
2841/// FunctionProtoType - Represents a prototype with parameter type info, e.g.
2842/// 'int foo(int)' or 'int foo(void)'.  'void' is represented as having no
2843/// parameters, not as having a single void parameter. Such a type can have an
2844/// exception specification, but this specification is not part of the canonical
2845/// type.
2846class FunctionProtoType : public FunctionType, public llvm::FoldingSetNode {
2847public:
2848  /// ExtProtoInfo - Extra information about a function prototype.
2849  struct ExtProtoInfo {
2850    ExtProtoInfo()
2851        : Variadic(false), HasTrailingReturn(false), TypeQuals(0),
2852          ExceptionSpecType(EST_None), RefQualifier(RQ_None), NumExceptions(0),
2853          Exceptions(0), NoexceptExpr(0), ExceptionSpecDecl(0),
2854          ExceptionSpecTemplate(0), ConsumedParameters(0) {}
2855
2856    ExtProtoInfo(CallingConv CC)
2857        : ExtInfo(CC), Variadic(false), HasTrailingReturn(false), TypeQuals(0),
2858          ExceptionSpecType(EST_None), RefQualifier(RQ_None), NumExceptions(0),
2859          Exceptions(0), NoexceptExpr(0), ExceptionSpecDecl(0),
2860          ExceptionSpecTemplate(0), ConsumedParameters(0) {}
2861
2862    FunctionType::ExtInfo ExtInfo;
2863    bool Variadic : 1;
2864    bool HasTrailingReturn : 1;
2865    unsigned char TypeQuals;
2866    ExceptionSpecificationType ExceptionSpecType;
2867    RefQualifierKind RefQualifier;
2868    unsigned NumExceptions;
2869    const QualType *Exceptions;
2870    Expr *NoexceptExpr;
2871    FunctionDecl *ExceptionSpecDecl;
2872    FunctionDecl *ExceptionSpecTemplate;
2873    const bool *ConsumedParameters;
2874  };
2875
2876private:
2877  /// \brief Determine whether there are any argument types that
2878  /// contain an unexpanded parameter pack.
2879  static bool containsAnyUnexpandedParameterPack(const QualType *ArgArray,
2880                                                 unsigned numArgs) {
2881    for (unsigned Idx = 0; Idx < numArgs; ++Idx)
2882      if (ArgArray[Idx]->containsUnexpandedParameterPack())
2883        return true;
2884
2885    return false;
2886  }
2887
2888  FunctionProtoType(QualType result, ArrayRef<QualType> params,
2889                    QualType canonical, const ExtProtoInfo &epi);
2890
2891  /// The number of parameters this function has, not counting '...'.
2892  unsigned NumParams : 15;
2893
2894  /// NumExceptions - The number of types in the exception spec, if any.
2895  unsigned NumExceptions : 9;
2896
2897  /// ExceptionSpecType - The type of exception specification this function has.
2898  unsigned ExceptionSpecType : 3;
2899
2900  /// HasAnyConsumedParams - Whether this function has any consumed parameters.
2901  unsigned HasAnyConsumedParams : 1;
2902
2903  /// Variadic - Whether the function is variadic.
2904  unsigned Variadic : 1;
2905
2906  /// HasTrailingReturn - Whether this function has a trailing return type.
2907  unsigned HasTrailingReturn : 1;
2908
2909  /// \brief The ref-qualifier associated with a \c FunctionProtoType.
2910  ///
2911  /// This is a value of type \c RefQualifierKind.
2912  unsigned RefQualifier : 2;
2913
2914  // ParamInfo - There is an variable size array after the class in memory that
2915  // holds the parameter types.
2916
2917  // Exceptions - There is another variable size array after ArgInfo that
2918  // holds the exception types.
2919
2920  // NoexceptExpr - Instead of Exceptions, there may be a single Expr* pointing
2921  // to the expression in the noexcept() specifier.
2922
2923  // ExceptionSpecDecl, ExceptionSpecTemplate - Instead of Exceptions, there may
2924  // be a pair of FunctionDecl* pointing to the function which should be used to
2925  // instantiate this function type's exception specification, and the function
2926  // from which it should be instantiated.
2927
2928  // ConsumedParameters - A variable size array, following Exceptions
2929  // and of length NumParams, holding flags indicating which parameters
2930  // are consumed.  This only appears if HasAnyConsumedParams is true.
2931
2932  friend class ASTContext;  // ASTContext creates these.
2933
2934  const bool *getConsumedParamsBuffer() const {
2935    assert(hasAnyConsumedParams());
2936
2937    // Find the end of the exceptions.
2938    Expr *const *eh_end = reinterpret_cast<Expr *const *>(param_type_end());
2939    if (getExceptionSpecType() != EST_ComputedNoexcept)
2940      eh_end += NumExceptions;
2941    else
2942      eh_end += 1; // NoexceptExpr
2943
2944    return reinterpret_cast<const bool*>(eh_end);
2945  }
2946
2947public:
2948  unsigned getNumParams() const { return NumParams; }
2949  QualType getParamType(unsigned i) const {
2950    assert(i < NumParams && "invalid parameter index");
2951    return param_type_begin()[i];
2952  }
2953  ArrayRef<QualType> getParamTypes() const {
2954    return ArrayRef<QualType>(param_type_begin(), param_type_end());
2955  }
2956
2957  ExtProtoInfo getExtProtoInfo() const {
2958    ExtProtoInfo EPI;
2959    EPI.ExtInfo = getExtInfo();
2960    EPI.Variadic = isVariadic();
2961    EPI.HasTrailingReturn = hasTrailingReturn();
2962    EPI.ExceptionSpecType = getExceptionSpecType();
2963    EPI.TypeQuals = static_cast<unsigned char>(getTypeQuals());
2964    EPI.RefQualifier = getRefQualifier();
2965    if (EPI.ExceptionSpecType == EST_Dynamic) {
2966      EPI.NumExceptions = NumExceptions;
2967      EPI.Exceptions = exception_begin();
2968    } else if (EPI.ExceptionSpecType == EST_ComputedNoexcept) {
2969      EPI.NoexceptExpr = getNoexceptExpr();
2970    } else if (EPI.ExceptionSpecType == EST_Uninstantiated) {
2971      EPI.ExceptionSpecDecl = getExceptionSpecDecl();
2972      EPI.ExceptionSpecTemplate = getExceptionSpecTemplate();
2973    } else if (EPI.ExceptionSpecType == EST_Unevaluated) {
2974      EPI.ExceptionSpecDecl = getExceptionSpecDecl();
2975    }
2976    if (hasAnyConsumedParams())
2977      EPI.ConsumedParameters = getConsumedParamsBuffer();
2978    return EPI;
2979  }
2980
2981  /// \brief Get the kind of exception specification on this function.
2982  ExceptionSpecificationType getExceptionSpecType() const {
2983    return static_cast<ExceptionSpecificationType>(ExceptionSpecType);
2984  }
2985  /// \brief Return whether this function has any kind of exception spec.
2986  bool hasExceptionSpec() const {
2987    return getExceptionSpecType() != EST_None;
2988  }
2989  /// \brief Return whether this function has a dynamic (throw) exception spec.
2990  bool hasDynamicExceptionSpec() const {
2991    return isDynamicExceptionSpec(getExceptionSpecType());
2992  }
2993  /// \brief Return whether this function has a noexcept exception spec.
2994  bool hasNoexceptExceptionSpec() const {
2995    return isNoexceptExceptionSpec(getExceptionSpecType());
2996  }
2997  /// \brief Result type of getNoexceptSpec().
2998  enum NoexceptResult {
2999    NR_NoNoexcept,  ///< There is no noexcept specifier.
3000    NR_BadNoexcept, ///< The noexcept specifier has a bad expression.
3001    NR_Dependent,   ///< The noexcept specifier is dependent.
3002    NR_Throw,       ///< The noexcept specifier evaluates to false.
3003    NR_Nothrow      ///< The noexcept specifier evaluates to true.
3004  };
3005  /// \brief Get the meaning of the noexcept spec on this function, if any.
3006  NoexceptResult getNoexceptSpec(const ASTContext &Ctx) const;
3007  unsigned getNumExceptions() const { return NumExceptions; }
3008  QualType getExceptionType(unsigned i) const {
3009    assert(i < NumExceptions && "Invalid exception number!");
3010    return exception_begin()[i];
3011  }
3012  Expr *getNoexceptExpr() const {
3013    if (getExceptionSpecType() != EST_ComputedNoexcept)
3014      return 0;
3015    // NoexceptExpr sits where the arguments end.
3016    return *reinterpret_cast<Expr *const *>(param_type_end());
3017  }
3018  /// \brief If this function type has an exception specification which hasn't
3019  /// been determined yet (either because it has not been evaluated or because
3020  /// it has not been instantiated), this is the function whose exception
3021  /// specification is represented by this type.
3022  FunctionDecl *getExceptionSpecDecl() const {
3023    if (getExceptionSpecType() != EST_Uninstantiated &&
3024        getExceptionSpecType() != EST_Unevaluated)
3025      return 0;
3026    return reinterpret_cast<FunctionDecl *const *>(param_type_end())[0];
3027  }
3028  /// \brief If this function type has an uninstantiated exception
3029  /// specification, this is the function whose exception specification
3030  /// should be instantiated to find the exception specification for
3031  /// this type.
3032  FunctionDecl *getExceptionSpecTemplate() const {
3033    if (getExceptionSpecType() != EST_Uninstantiated)
3034      return 0;
3035    return reinterpret_cast<FunctionDecl *const *>(param_type_end())[1];
3036  }
3037  /// \brief Determine whether this function type has a non-throwing exception
3038  /// specification. If this depends on template arguments, returns
3039  /// \c ResultIfDependent.
3040  bool isNothrow(const ASTContext &Ctx, bool ResultIfDependent = false) const;
3041
3042  bool isVariadic() const { return Variadic; }
3043
3044  /// \brief Determines whether this function prototype contains a
3045  /// parameter pack at the end.
3046  ///
3047  /// A function template whose last parameter is a parameter pack can be
3048  /// called with an arbitrary number of arguments, much like a variadic
3049  /// function.
3050  bool isTemplateVariadic() const;
3051
3052  bool hasTrailingReturn() const { return HasTrailingReturn; }
3053
3054  unsigned getTypeQuals() const { return FunctionType::getTypeQuals(); }
3055
3056
3057  /// \brief Retrieve the ref-qualifier associated with this function type.
3058  RefQualifierKind getRefQualifier() const {
3059    return static_cast<RefQualifierKind>(RefQualifier);
3060  }
3061
3062  typedef const QualType *param_type_iterator;
3063  typedef llvm::iterator_range<param_type_iterator> param_type_range;
3064
3065  param_type_range param_types() const {
3066    return param_type_range(param_type_begin(), param_type_end());
3067  }
3068  param_type_iterator param_type_begin() const {
3069    return reinterpret_cast<const QualType *>(this+1);
3070  }
3071  param_type_iterator param_type_end() const {
3072    return param_type_begin() + NumParams;
3073  }
3074
3075  typedef const QualType *exception_iterator;
3076  typedef llvm::iterator_range<exception_iterator> exception_range;
3077
3078  exception_range exceptions() const {
3079    return exception_range(exception_begin(), exception_end());
3080  }
3081  exception_iterator exception_begin() const {
3082    // exceptions begin where arguments end
3083    return param_type_end();
3084  }
3085  exception_iterator exception_end() const {
3086    if (getExceptionSpecType() != EST_Dynamic)
3087      return exception_begin();
3088    return exception_begin() + NumExceptions;
3089  }
3090
3091  bool hasAnyConsumedParams() const { return HasAnyConsumedParams; }
3092  bool isParamConsumed(unsigned I) const {
3093    assert(I < getNumParams() && "parameter index out of range");
3094    if (hasAnyConsumedParams())
3095      return getConsumedParamsBuffer()[I];
3096    return false;
3097  }
3098
3099  bool isSugared() const { return false; }
3100  QualType desugar() const { return QualType(this, 0); }
3101
3102  void printExceptionSpecification(raw_ostream &OS,
3103                                   const PrintingPolicy &Policy) const;
3104
3105  static bool classof(const Type *T) {
3106    return T->getTypeClass() == FunctionProto;
3107  }
3108
3109  void Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Ctx);
3110  static void Profile(llvm::FoldingSetNodeID &ID, QualType Result,
3111                      param_type_iterator ArgTys, unsigned NumArgs,
3112                      const ExtProtoInfo &EPI, const ASTContext &Context);
3113};
3114
3115
3116/// \brief Represents the dependent type named by a dependently-scoped
3117/// typename using declaration, e.g.
3118///   using typename Base<T>::foo;
3119/// Template instantiation turns these into the underlying type.
3120class UnresolvedUsingType : public Type {
3121  UnresolvedUsingTypenameDecl *Decl;
3122
3123  UnresolvedUsingType(const UnresolvedUsingTypenameDecl *D)
3124    : Type(UnresolvedUsing, QualType(), true, true, false,
3125           /*ContainsUnexpandedParameterPack=*/false),
3126      Decl(const_cast<UnresolvedUsingTypenameDecl*>(D)) {}
3127  friend class ASTContext; // ASTContext creates these.
3128public:
3129
3130  UnresolvedUsingTypenameDecl *getDecl() const { return Decl; }
3131
3132  bool isSugared() const { return false; }
3133  QualType desugar() const { return QualType(this, 0); }
3134
3135  static bool classof(const Type *T) {
3136    return T->getTypeClass() == UnresolvedUsing;
3137  }
3138
3139  void Profile(llvm::FoldingSetNodeID &ID) {
3140    return Profile(ID, Decl);
3141  }
3142  static void Profile(llvm::FoldingSetNodeID &ID,
3143                      UnresolvedUsingTypenameDecl *D) {
3144    ID.AddPointer(D);
3145  }
3146};
3147
3148
3149class TypedefType : public Type {
3150  TypedefNameDecl *Decl;
3151protected:
3152  TypedefType(TypeClass tc, const TypedefNameDecl *D, QualType can)
3153    : Type(tc, can, can->isDependentType(),
3154           can->isInstantiationDependentType(),
3155           can->isVariablyModifiedType(),
3156           /*ContainsUnexpandedParameterPack=*/false),
3157      Decl(const_cast<TypedefNameDecl*>(D)) {
3158    assert(!isa<TypedefType>(can) && "Invalid canonical type");
3159  }
3160  friend class ASTContext;  // ASTContext creates these.
3161public:
3162
3163  TypedefNameDecl *getDecl() const { return Decl; }
3164
3165  bool isSugared() const { return true; }
3166  QualType desugar() const;
3167
3168  static bool classof(const Type *T) { return T->getTypeClass() == Typedef; }
3169};
3170
3171/// TypeOfExprType (GCC extension).
3172class TypeOfExprType : public Type {
3173  Expr *TOExpr;
3174
3175protected:
3176  TypeOfExprType(Expr *E, QualType can = QualType());
3177  friend class ASTContext;  // ASTContext creates these.
3178public:
3179  Expr *getUnderlyingExpr() const { return TOExpr; }
3180
3181  /// \brief Remove a single level of sugar.
3182  QualType desugar() const;
3183
3184  /// \brief Returns whether this type directly provides sugar.
3185  bool isSugared() const;
3186
3187  static bool classof(const Type *T) { return T->getTypeClass() == TypeOfExpr; }
3188};
3189
3190/// \brief Internal representation of canonical, dependent
3191/// typeof(expr) types.
3192///
3193/// This class is used internally by the ASTContext to manage
3194/// canonical, dependent types, only. Clients will only see instances
3195/// of this class via TypeOfExprType nodes.
3196class DependentTypeOfExprType
3197  : public TypeOfExprType, public llvm::FoldingSetNode {
3198  const ASTContext &Context;
3199
3200public:
3201  DependentTypeOfExprType(const ASTContext &Context, Expr *E)
3202    : TypeOfExprType(E), Context(Context) { }
3203
3204  void Profile(llvm::FoldingSetNodeID &ID) {
3205    Profile(ID, Context, getUnderlyingExpr());
3206  }
3207
3208  static void Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Context,
3209                      Expr *E);
3210};
3211
3212/// TypeOfType (GCC extension).
3213class TypeOfType : public Type {
3214  QualType TOType;
3215  TypeOfType(QualType T, QualType can)
3216    : Type(TypeOf, can, T->isDependentType(),
3217           T->isInstantiationDependentType(),
3218           T->isVariablyModifiedType(),
3219           T->containsUnexpandedParameterPack()),
3220      TOType(T) {
3221    assert(!isa<TypedefType>(can) && "Invalid canonical type");
3222  }
3223  friend class ASTContext;  // ASTContext creates these.
3224public:
3225  QualType getUnderlyingType() const { return TOType; }
3226
3227  /// \brief Remove a single level of sugar.
3228  QualType desugar() const { return getUnderlyingType(); }
3229
3230  /// \brief Returns whether this type directly provides sugar.
3231  bool isSugared() const { return true; }
3232
3233  static bool classof(const Type *T) { return T->getTypeClass() == TypeOf; }
3234};
3235
3236/// DecltypeType (C++0x)
3237class DecltypeType : public Type {
3238  Expr *E;
3239  QualType UnderlyingType;
3240
3241protected:
3242  DecltypeType(Expr *E, QualType underlyingType, QualType can = QualType());
3243  friend class ASTContext;  // ASTContext creates these.
3244public:
3245  Expr *getUnderlyingExpr() const { return E; }
3246  QualType getUnderlyingType() const { return UnderlyingType; }
3247
3248  /// \brief Remove a single level of sugar.
3249  QualType desugar() const;
3250
3251  /// \brief Returns whether this type directly provides sugar.
3252  bool isSugared() const;
3253
3254  static bool classof(const Type *T) { return T->getTypeClass() == Decltype; }
3255};
3256
3257/// \brief Internal representation of canonical, dependent
3258/// decltype(expr) types.
3259///
3260/// This class is used internally by the ASTContext to manage
3261/// canonical, dependent types, only. Clients will only see instances
3262/// of this class via DecltypeType nodes.
3263class DependentDecltypeType : public DecltypeType, public llvm::FoldingSetNode {
3264  const ASTContext &Context;
3265
3266public:
3267  DependentDecltypeType(const ASTContext &Context, Expr *E);
3268
3269  void Profile(llvm::FoldingSetNodeID &ID) {
3270    Profile(ID, Context, getUnderlyingExpr());
3271  }
3272
3273  static void Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Context,
3274                      Expr *E);
3275};
3276
3277/// \brief A unary type transform, which is a type constructed from another
3278class UnaryTransformType : public Type {
3279public:
3280  enum UTTKind {
3281    EnumUnderlyingType
3282  };
3283
3284private:
3285  /// The untransformed type.
3286  QualType BaseType;
3287  /// The transformed type if not dependent, otherwise the same as BaseType.
3288  QualType UnderlyingType;
3289
3290  UTTKind UKind;
3291protected:
3292  UnaryTransformType(QualType BaseTy, QualType UnderlyingTy, UTTKind UKind,
3293                     QualType CanonicalTy);
3294  friend class ASTContext;
3295public:
3296  bool isSugared() const { return !isDependentType(); }
3297  QualType desugar() const { return UnderlyingType; }
3298
3299  QualType getUnderlyingType() const { return UnderlyingType; }
3300  QualType getBaseType() const { return BaseType; }
3301
3302  UTTKind getUTTKind() const { return UKind; }
3303
3304  static bool classof(const Type *T) {
3305    return T->getTypeClass() == UnaryTransform;
3306  }
3307};
3308
3309class TagType : public Type {
3310  /// Stores the TagDecl associated with this type. The decl may point to any
3311  /// TagDecl that declares the entity.
3312  TagDecl * decl;
3313
3314  friend class ASTReader;
3315
3316protected:
3317  TagType(TypeClass TC, const TagDecl *D, QualType can);
3318
3319public:
3320  TagDecl *getDecl() const;
3321
3322  /// @brief Determines whether this type is in the process of being
3323  /// defined.
3324  bool isBeingDefined() const;
3325
3326  static bool classof(const Type *T) {
3327    return T->getTypeClass() >= TagFirst && T->getTypeClass() <= TagLast;
3328  }
3329};
3330
3331/// RecordType - This is a helper class that allows the use of isa/cast/dyncast
3332/// to detect TagType objects of structs/unions/classes.
3333class RecordType : public TagType {
3334protected:
3335  explicit RecordType(const RecordDecl *D)
3336    : TagType(Record, reinterpret_cast<const TagDecl*>(D), QualType()) { }
3337  explicit RecordType(TypeClass TC, RecordDecl *D)
3338    : TagType(TC, reinterpret_cast<const TagDecl*>(D), QualType()) { }
3339  friend class ASTContext;   // ASTContext creates these.
3340public:
3341
3342  RecordDecl *getDecl() const {
3343    return reinterpret_cast<RecordDecl*>(TagType::getDecl());
3344  }
3345
3346  // FIXME: This predicate is a helper to QualType/Type. It needs to
3347  // recursively check all fields for const-ness. If any field is declared
3348  // const, it needs to return false.
3349  bool hasConstFields() const { return false; }
3350
3351  bool isSugared() const { return false; }
3352  QualType desugar() const { return QualType(this, 0); }
3353
3354  static bool classof(const Type *T) { return T->getTypeClass() == Record; }
3355};
3356
3357/// EnumType - This is a helper class that allows the use of isa/cast/dyncast
3358/// to detect TagType objects of enums.
3359class EnumType : public TagType {
3360  explicit EnumType(const EnumDecl *D)
3361    : TagType(Enum, reinterpret_cast<const TagDecl*>(D), QualType()) { }
3362  friend class ASTContext;   // ASTContext creates these.
3363public:
3364
3365  EnumDecl *getDecl() const {
3366    return reinterpret_cast<EnumDecl*>(TagType::getDecl());
3367  }
3368
3369  bool isSugared() const { return false; }
3370  QualType desugar() const { return QualType(this, 0); }
3371
3372  static bool classof(const Type *T) { return T->getTypeClass() == Enum; }
3373};
3374
3375/// AttributedType - An attributed type is a type to which a type
3376/// attribute has been applied.  The "modified type" is the
3377/// fully-sugared type to which the attributed type was applied;
3378/// generally it is not canonically equivalent to the attributed type.
3379/// The "equivalent type" is the minimally-desugared type which the
3380/// type is canonically equivalent to.
3381///
3382/// For example, in the following attributed type:
3383///     int32_t __attribute__((vector_size(16)))
3384///   - the modified type is the TypedefType for int32_t
3385///   - the equivalent type is VectorType(16, int32_t)
3386///   - the canonical type is VectorType(16, int)
3387class AttributedType : public Type, public llvm::FoldingSetNode {
3388public:
3389  // It is really silly to have yet another attribute-kind enum, but
3390  // clang::attr::Kind doesn't currently cover the pure type attrs.
3391  enum Kind {
3392    // Expression operand.
3393    attr_address_space,
3394    attr_regparm,
3395    attr_vector_size,
3396    attr_neon_vector_type,
3397    attr_neon_polyvector_type,
3398
3399    FirstExprOperandKind = attr_address_space,
3400    LastExprOperandKind = attr_neon_polyvector_type,
3401
3402    // Enumerated operand (string or keyword).
3403    attr_objc_gc,
3404    attr_objc_ownership,
3405    attr_pcs,
3406    attr_pcs_vfp,
3407
3408    FirstEnumOperandKind = attr_objc_gc,
3409    LastEnumOperandKind = attr_pcs_vfp,
3410
3411    // No operand.
3412    attr_noreturn,
3413    attr_cdecl,
3414    attr_fastcall,
3415    attr_stdcall,
3416    attr_thiscall,
3417    attr_pascal,
3418    attr_pnaclcall,
3419    attr_inteloclbicc,
3420    attr_ms_abi,
3421    attr_sysv_abi,
3422    attr_ptr32,
3423    attr_ptr64,
3424    attr_sptr,
3425    attr_uptr
3426  };
3427
3428private:
3429  QualType ModifiedType;
3430  QualType EquivalentType;
3431
3432  friend class ASTContext; // creates these
3433
3434  AttributedType(QualType canon, Kind attrKind,
3435                 QualType modified, QualType equivalent)
3436    : Type(Attributed, canon, canon->isDependentType(),
3437           canon->isInstantiationDependentType(),
3438           canon->isVariablyModifiedType(),
3439           canon->containsUnexpandedParameterPack()),
3440      ModifiedType(modified), EquivalentType(equivalent) {
3441    AttributedTypeBits.AttrKind = attrKind;
3442  }
3443
3444public:
3445  Kind getAttrKind() const {
3446    return static_cast<Kind>(AttributedTypeBits.AttrKind);
3447  }
3448
3449  QualType getModifiedType() const { return ModifiedType; }
3450  QualType getEquivalentType() const { return EquivalentType; }
3451
3452  bool isSugared() const { return true; }
3453  QualType desugar() const { return getEquivalentType(); }
3454
3455  bool isMSTypeSpec() const;
3456
3457  bool isCallingConv() const;
3458
3459  void Profile(llvm::FoldingSetNodeID &ID) {
3460    Profile(ID, getAttrKind(), ModifiedType, EquivalentType);
3461  }
3462
3463  static void Profile(llvm::FoldingSetNodeID &ID, Kind attrKind,
3464                      QualType modified, QualType equivalent) {
3465    ID.AddInteger(attrKind);
3466    ID.AddPointer(modified.getAsOpaquePtr());
3467    ID.AddPointer(equivalent.getAsOpaquePtr());
3468  }
3469
3470  static bool classof(const Type *T) {
3471    return T->getTypeClass() == Attributed;
3472  }
3473};
3474
3475class TemplateTypeParmType : public Type, public llvm::FoldingSetNode {
3476  // Helper data collector for canonical types.
3477  struct CanonicalTTPTInfo {
3478    unsigned Depth : 15;
3479    unsigned ParameterPack : 1;
3480    unsigned Index : 16;
3481  };
3482
3483  union {
3484    // Info for the canonical type.
3485    CanonicalTTPTInfo CanTTPTInfo;
3486    // Info for the non-canonical type.
3487    TemplateTypeParmDecl *TTPDecl;
3488  };
3489
3490  /// Build a non-canonical type.
3491  TemplateTypeParmType(TemplateTypeParmDecl *TTPDecl, QualType Canon)
3492    : Type(TemplateTypeParm, Canon, /*Dependent=*/true,
3493           /*InstantiationDependent=*/true,
3494           /*VariablyModified=*/false,
3495           Canon->containsUnexpandedParameterPack()),
3496      TTPDecl(TTPDecl) { }
3497
3498  /// Build the canonical type.
3499  TemplateTypeParmType(unsigned D, unsigned I, bool PP)
3500    : Type(TemplateTypeParm, QualType(this, 0),
3501           /*Dependent=*/true,
3502           /*InstantiationDependent=*/true,
3503           /*VariablyModified=*/false, PP) {
3504    CanTTPTInfo.Depth = D;
3505    CanTTPTInfo.Index = I;
3506    CanTTPTInfo.ParameterPack = PP;
3507  }
3508
3509  friend class ASTContext;  // ASTContext creates these
3510
3511  const CanonicalTTPTInfo& getCanTTPTInfo() const {
3512    QualType Can = getCanonicalTypeInternal();
3513    return Can->castAs<TemplateTypeParmType>()->CanTTPTInfo;
3514  }
3515
3516public:
3517  unsigned getDepth() const { return getCanTTPTInfo().Depth; }
3518  unsigned getIndex() const { return getCanTTPTInfo().Index; }
3519  bool isParameterPack() const { return getCanTTPTInfo().ParameterPack; }
3520
3521  TemplateTypeParmDecl *getDecl() const {
3522    return isCanonicalUnqualified() ? 0 : TTPDecl;
3523  }
3524
3525  IdentifierInfo *getIdentifier() const;
3526
3527  bool isSugared() const { return false; }
3528  QualType desugar() const { return QualType(this, 0); }
3529
3530  void Profile(llvm::FoldingSetNodeID &ID) {
3531    Profile(ID, getDepth(), getIndex(), isParameterPack(), getDecl());
3532  }
3533
3534  static void Profile(llvm::FoldingSetNodeID &ID, unsigned Depth,
3535                      unsigned Index, bool ParameterPack,
3536                      TemplateTypeParmDecl *TTPDecl) {
3537    ID.AddInteger(Depth);
3538    ID.AddInteger(Index);
3539    ID.AddBoolean(ParameterPack);
3540    ID.AddPointer(TTPDecl);
3541  }
3542
3543  static bool classof(const Type *T) {
3544    return T->getTypeClass() == TemplateTypeParm;
3545  }
3546};
3547
3548/// \brief Represents the result of substituting a type for a template
3549/// type parameter.
3550///
3551/// Within an instantiated template, all template type parameters have
3552/// been replaced with these.  They are used solely to record that a
3553/// type was originally written as a template type parameter;
3554/// therefore they are never canonical.
3555class SubstTemplateTypeParmType : public Type, public llvm::FoldingSetNode {
3556  // The original type parameter.
3557  const TemplateTypeParmType *Replaced;
3558
3559  SubstTemplateTypeParmType(const TemplateTypeParmType *Param, QualType Canon)
3560    : Type(SubstTemplateTypeParm, Canon, Canon->isDependentType(),
3561           Canon->isInstantiationDependentType(),
3562           Canon->isVariablyModifiedType(),
3563           Canon->containsUnexpandedParameterPack()),
3564      Replaced(Param) { }
3565
3566  friend class ASTContext;
3567
3568public:
3569  /// Gets the template parameter that was substituted for.
3570  const TemplateTypeParmType *getReplacedParameter() const {
3571    return Replaced;
3572  }
3573
3574  /// Gets the type that was substituted for the template
3575  /// parameter.
3576  QualType getReplacementType() const {
3577    return getCanonicalTypeInternal();
3578  }
3579
3580  bool isSugared() const { return true; }
3581  QualType desugar() const { return getReplacementType(); }
3582
3583  void Profile(llvm::FoldingSetNodeID &ID) {
3584    Profile(ID, getReplacedParameter(), getReplacementType());
3585  }
3586  static void Profile(llvm::FoldingSetNodeID &ID,
3587                      const TemplateTypeParmType *Replaced,
3588                      QualType Replacement) {
3589    ID.AddPointer(Replaced);
3590    ID.AddPointer(Replacement.getAsOpaquePtr());
3591  }
3592
3593  static bool classof(const Type *T) {
3594    return T->getTypeClass() == SubstTemplateTypeParm;
3595  }
3596};
3597
3598/// \brief Represents the result of substituting a set of types for a template
3599/// type parameter pack.
3600///
3601/// When a pack expansion in the source code contains multiple parameter packs
3602/// and those parameter packs correspond to different levels of template
3603/// parameter lists, this type node is used to represent a template type
3604/// parameter pack from an outer level, which has already had its argument pack
3605/// substituted but that still lives within a pack expansion that itself
3606/// could not be instantiated. When actually performing a substitution into
3607/// that pack expansion (e.g., when all template parameters have corresponding
3608/// arguments), this type will be replaced with the \c SubstTemplateTypeParmType
3609/// at the current pack substitution index.
3610class SubstTemplateTypeParmPackType : public Type, public llvm::FoldingSetNode {
3611  /// \brief The original type parameter.
3612  const TemplateTypeParmType *Replaced;
3613
3614  /// \brief A pointer to the set of template arguments that this
3615  /// parameter pack is instantiated with.
3616  const TemplateArgument *Arguments;
3617
3618  /// \brief The number of template arguments in \c Arguments.
3619  unsigned NumArguments;
3620
3621  SubstTemplateTypeParmPackType(const TemplateTypeParmType *Param,
3622                                QualType Canon,
3623                                const TemplateArgument &ArgPack);
3624
3625  friend class ASTContext;
3626
3627public:
3628  IdentifierInfo *getIdentifier() const { return Replaced->getIdentifier(); }
3629
3630  /// Gets the template parameter that was substituted for.
3631  const TemplateTypeParmType *getReplacedParameter() const {
3632    return Replaced;
3633  }
3634
3635  bool isSugared() const { return false; }
3636  QualType desugar() const { return QualType(this, 0); }
3637
3638  TemplateArgument getArgumentPack() const;
3639
3640  void Profile(llvm::FoldingSetNodeID &ID);
3641  static void Profile(llvm::FoldingSetNodeID &ID,
3642                      const TemplateTypeParmType *Replaced,
3643                      const TemplateArgument &ArgPack);
3644
3645  static bool classof(const Type *T) {
3646    return T->getTypeClass() == SubstTemplateTypeParmPack;
3647  }
3648};
3649
3650/// \brief Represents a C++11 auto or C++1y decltype(auto) type.
3651///
3652/// These types are usually a placeholder for a deduced type. However, before
3653/// the initializer is attached, or if the initializer is type-dependent, there
3654/// is no deduced type and an auto type is canonical. In the latter case, it is
3655/// also a dependent type.
3656class AutoType : public Type, public llvm::FoldingSetNode {
3657  AutoType(QualType DeducedType, bool IsDecltypeAuto,
3658           bool IsDependent)
3659    : Type(Auto, DeducedType.isNull() ? QualType(this, 0) : DeducedType,
3660           /*Dependent=*/IsDependent, /*InstantiationDependent=*/IsDependent,
3661           /*VariablyModified=*/false,
3662           /*ContainsParameterPack=*/DeducedType.isNull()
3663               ? false : DeducedType->containsUnexpandedParameterPack()) {
3664    assert((DeducedType.isNull() || !IsDependent) &&
3665           "auto deduced to dependent type");
3666    AutoTypeBits.IsDecltypeAuto = IsDecltypeAuto;
3667  }
3668
3669  friend class ASTContext;  // ASTContext creates these
3670
3671public:
3672  bool isDecltypeAuto() const { return AutoTypeBits.IsDecltypeAuto; }
3673
3674  bool isSugared() const { return !isCanonicalUnqualified(); }
3675  QualType desugar() const { return getCanonicalTypeInternal(); }
3676
3677  /// \brief Get the type deduced for this auto type, or null if it's either
3678  /// not been deduced or was deduced to a dependent type.
3679  QualType getDeducedType() const {
3680    return !isCanonicalUnqualified() ? getCanonicalTypeInternal() : QualType();
3681  }
3682  bool isDeduced() const {
3683    return !isCanonicalUnqualified() || isDependentType();
3684  }
3685
3686  void Profile(llvm::FoldingSetNodeID &ID) {
3687    Profile(ID, getDeducedType(), isDecltypeAuto(),
3688		    isDependentType());
3689  }
3690
3691  static void Profile(llvm::FoldingSetNodeID &ID, QualType Deduced,
3692                      bool IsDecltypeAuto, bool IsDependent) {
3693    ID.AddPointer(Deduced.getAsOpaquePtr());
3694    ID.AddBoolean(IsDecltypeAuto);
3695    ID.AddBoolean(IsDependent);
3696  }
3697
3698  static bool classof(const Type *T) {
3699    return T->getTypeClass() == Auto;
3700  }
3701};
3702
3703/// \brief Represents a type template specialization; the template
3704/// must be a class template, a type alias template, or a template
3705/// template parameter.  A template which cannot be resolved to one of
3706/// these, e.g. because it is written with a dependent scope
3707/// specifier, is instead represented as a
3708/// @c DependentTemplateSpecializationType.
3709///
3710/// A non-dependent template specialization type is always "sugar",
3711/// typically for a @c RecordType.  For example, a class template
3712/// specialization type of @c vector<int> will refer to a tag type for
3713/// the instantiation @c std::vector<int, std::allocator<int>>
3714///
3715/// Template specializations are dependent if either the template or
3716/// any of the template arguments are dependent, in which case the
3717/// type may also be canonical.
3718///
3719/// Instances of this type are allocated with a trailing array of
3720/// TemplateArguments, followed by a QualType representing the
3721/// non-canonical aliased type when the template is a type alias
3722/// template.
3723class TemplateSpecializationType
3724  : public Type, public llvm::FoldingSetNode {
3725  /// \brief The name of the template being specialized.  This is
3726  /// either a TemplateName::Template (in which case it is a
3727  /// ClassTemplateDecl*, a TemplateTemplateParmDecl*, or a
3728  /// TypeAliasTemplateDecl*), a
3729  /// TemplateName::SubstTemplateTemplateParmPack, or a
3730  /// TemplateName::SubstTemplateTemplateParm (in which case the
3731  /// replacement must, recursively, be one of these).
3732  TemplateName Template;
3733
3734  /// \brief - The number of template arguments named in this class
3735  /// template specialization.
3736  unsigned NumArgs : 31;
3737
3738  /// \brief Whether this template specialization type is a substituted
3739  /// type alias.
3740  bool TypeAlias : 1;
3741
3742  TemplateSpecializationType(TemplateName T,
3743                             const TemplateArgument *Args,
3744                             unsigned NumArgs, QualType Canon,
3745                             QualType Aliased);
3746
3747  friend class ASTContext;  // ASTContext creates these
3748
3749public:
3750  /// \brief Determine whether any of the given template arguments are
3751  /// dependent.
3752  static bool anyDependentTemplateArguments(const TemplateArgumentLoc *Args,
3753                                            unsigned NumArgs,
3754                                            bool &InstantiationDependent);
3755
3756  static bool anyDependentTemplateArguments(const TemplateArgumentListInfo &,
3757                                            bool &InstantiationDependent);
3758
3759  /// \brief Print a template argument list, including the '<' and '>'
3760  /// enclosing the template arguments.
3761  static void PrintTemplateArgumentList(raw_ostream &OS,
3762                                        const TemplateArgument *Args,
3763                                        unsigned NumArgs,
3764                                        const PrintingPolicy &Policy,
3765                                        bool SkipBrackets = false);
3766
3767  static void PrintTemplateArgumentList(raw_ostream &OS,
3768                                        const TemplateArgumentLoc *Args,
3769                                        unsigned NumArgs,
3770                                        const PrintingPolicy &Policy);
3771
3772  static void PrintTemplateArgumentList(raw_ostream &OS,
3773                                        const TemplateArgumentListInfo &,
3774                                        const PrintingPolicy &Policy);
3775
3776  /// True if this template specialization type matches a current
3777  /// instantiation in the context in which it is found.
3778  bool isCurrentInstantiation() const {
3779    return isa<InjectedClassNameType>(getCanonicalTypeInternal());
3780  }
3781
3782  /// \brief Determine if this template specialization type is for a type alias
3783  /// template that has been substituted.
3784  ///
3785  /// Nearly every template specialization type whose template is an alias
3786  /// template will be substituted. However, this is not the case when
3787  /// the specialization contains a pack expansion but the template alias
3788  /// does not have a corresponding parameter pack, e.g.,
3789  ///
3790  /// \code
3791  /// template<typename T, typename U, typename V> struct S;
3792  /// template<typename T, typename U> using A = S<T, int, U>;
3793  /// template<typename... Ts> struct X {
3794  ///   typedef A<Ts...> type; // not a type alias
3795  /// };
3796  /// \endcode
3797  bool isTypeAlias() const { return TypeAlias; }
3798
3799  /// Get the aliased type, if this is a specialization of a type alias
3800  /// template.
3801  QualType getAliasedType() const {
3802    assert(isTypeAlias() && "not a type alias template specialization");
3803    return *reinterpret_cast<const QualType*>(end());
3804  }
3805
3806  typedef const TemplateArgument * iterator;
3807
3808  iterator begin() const { return getArgs(); }
3809  iterator end() const; // defined inline in TemplateBase.h
3810
3811  /// \brief Retrieve the name of the template that we are specializing.
3812  TemplateName getTemplateName() const { return Template; }
3813
3814  /// \brief Retrieve the template arguments.
3815  const TemplateArgument *getArgs() const {
3816    return reinterpret_cast<const TemplateArgument *>(this + 1);
3817  }
3818
3819  /// \brief Retrieve the number of template arguments.
3820  unsigned getNumArgs() const { return NumArgs; }
3821
3822  /// \brief Retrieve a specific template argument as a type.
3823  /// \pre @c isArgType(Arg)
3824  const TemplateArgument &getArg(unsigned Idx) const; // in TemplateBase.h
3825
3826  bool isSugared() const {
3827    return !isDependentType() || isCurrentInstantiation() || isTypeAlias();
3828  }
3829  QualType desugar() const { return getCanonicalTypeInternal(); }
3830
3831  void Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Ctx) {
3832    Profile(ID, Template, getArgs(), NumArgs, Ctx);
3833    if (isTypeAlias())
3834      getAliasedType().Profile(ID);
3835  }
3836
3837  static void Profile(llvm::FoldingSetNodeID &ID, TemplateName T,
3838                      const TemplateArgument *Args,
3839                      unsigned NumArgs,
3840                      const ASTContext &Context);
3841
3842  static bool classof(const Type *T) {
3843    return T->getTypeClass() == TemplateSpecialization;
3844  }
3845};
3846
3847/// \brief The injected class name of a C++ class template or class
3848/// template partial specialization.  Used to record that a type was
3849/// spelled with a bare identifier rather than as a template-id; the
3850/// equivalent for non-templated classes is just RecordType.
3851///
3852/// Injected class name types are always dependent.  Template
3853/// instantiation turns these into RecordTypes.
3854///
3855/// Injected class name types are always canonical.  This works
3856/// because it is impossible to compare an injected class name type
3857/// with the corresponding non-injected template type, for the same
3858/// reason that it is impossible to directly compare template
3859/// parameters from different dependent contexts: injected class name
3860/// types can only occur within the scope of a particular templated
3861/// declaration, and within that scope every template specialization
3862/// will canonicalize to the injected class name (when appropriate
3863/// according to the rules of the language).
3864class InjectedClassNameType : public Type {
3865  CXXRecordDecl *Decl;
3866
3867  /// The template specialization which this type represents.
3868  /// For example, in
3869  ///   template <class T> class A { ... };
3870  /// this is A<T>, whereas in
3871  ///   template <class X, class Y> class A<B<X,Y> > { ... };
3872  /// this is A<B<X,Y> >.
3873  ///
3874  /// It is always unqualified, always a template specialization type,
3875  /// and always dependent.
3876  QualType InjectedType;
3877
3878  friend class ASTContext; // ASTContext creates these.
3879  friend class ASTReader; // FIXME: ASTContext::getInjectedClassNameType is not
3880                          // currently suitable for AST reading, too much
3881                          // interdependencies.
3882  InjectedClassNameType(CXXRecordDecl *D, QualType TST)
3883    : Type(InjectedClassName, QualType(), /*Dependent=*/true,
3884           /*InstantiationDependent=*/true,
3885           /*VariablyModified=*/false,
3886           /*ContainsUnexpandedParameterPack=*/false),
3887      Decl(D), InjectedType(TST) {
3888    assert(isa<TemplateSpecializationType>(TST));
3889    assert(!TST.hasQualifiers());
3890    assert(TST->isDependentType());
3891  }
3892
3893public:
3894  QualType getInjectedSpecializationType() const { return InjectedType; }
3895  const TemplateSpecializationType *getInjectedTST() const {
3896    return cast<TemplateSpecializationType>(InjectedType.getTypePtr());
3897  }
3898
3899  CXXRecordDecl *getDecl() const;
3900
3901  bool isSugared() const { return false; }
3902  QualType desugar() const { return QualType(this, 0); }
3903
3904  static bool classof(const Type *T) {
3905    return T->getTypeClass() == InjectedClassName;
3906  }
3907};
3908
3909/// \brief The kind of a tag type.
3910enum TagTypeKind {
3911  /// \brief The "struct" keyword.
3912  TTK_Struct,
3913  /// \brief The "__interface" keyword.
3914  TTK_Interface,
3915  /// \brief The "union" keyword.
3916  TTK_Union,
3917  /// \brief The "class" keyword.
3918  TTK_Class,
3919  /// \brief The "enum" keyword.
3920  TTK_Enum
3921};
3922
3923/// \brief The elaboration keyword that precedes a qualified type name or
3924/// introduces an elaborated-type-specifier.
3925enum ElaboratedTypeKeyword {
3926  /// \brief The "struct" keyword introduces the elaborated-type-specifier.
3927  ETK_Struct,
3928  /// \brief The "__interface" keyword introduces the elaborated-type-specifier.
3929  ETK_Interface,
3930  /// \brief The "union" keyword introduces the elaborated-type-specifier.
3931  ETK_Union,
3932  /// \brief The "class" keyword introduces the elaborated-type-specifier.
3933  ETK_Class,
3934  /// \brief The "enum" keyword introduces the elaborated-type-specifier.
3935  ETK_Enum,
3936  /// \brief The "typename" keyword precedes the qualified type name, e.g.,
3937  /// \c typename T::type.
3938  ETK_Typename,
3939  /// \brief No keyword precedes the qualified type name.
3940  ETK_None
3941};
3942
3943/// A helper class for Type nodes having an ElaboratedTypeKeyword.
3944/// The keyword in stored in the free bits of the base class.
3945/// Also provides a few static helpers for converting and printing
3946/// elaborated type keyword and tag type kind enumerations.
3947class TypeWithKeyword : public Type {
3948protected:
3949  TypeWithKeyword(ElaboratedTypeKeyword Keyword, TypeClass tc,
3950                  QualType Canonical, bool Dependent,
3951                  bool InstantiationDependent, bool VariablyModified,
3952                  bool ContainsUnexpandedParameterPack)
3953  : Type(tc, Canonical, Dependent, InstantiationDependent, VariablyModified,
3954         ContainsUnexpandedParameterPack) {
3955    TypeWithKeywordBits.Keyword = Keyword;
3956  }
3957
3958public:
3959  ElaboratedTypeKeyword getKeyword() const {
3960    return static_cast<ElaboratedTypeKeyword>(TypeWithKeywordBits.Keyword);
3961  }
3962
3963  /// getKeywordForTypeSpec - Converts a type specifier (DeclSpec::TST)
3964  /// into an elaborated type keyword.
3965  static ElaboratedTypeKeyword getKeywordForTypeSpec(unsigned TypeSpec);
3966
3967  /// getTagTypeKindForTypeSpec - Converts a type specifier (DeclSpec::TST)
3968  /// into a tag type kind.  It is an error to provide a type specifier
3969  /// which *isn't* a tag kind here.
3970  static TagTypeKind getTagTypeKindForTypeSpec(unsigned TypeSpec);
3971
3972  /// getKeywordForTagDeclKind - Converts a TagTypeKind into an
3973  /// elaborated type keyword.
3974  static ElaboratedTypeKeyword getKeywordForTagTypeKind(TagTypeKind Tag);
3975
3976  /// getTagTypeKindForKeyword - Converts an elaborated type keyword into
3977  // a TagTypeKind. It is an error to provide an elaborated type keyword
3978  /// which *isn't* a tag kind here.
3979  static TagTypeKind getTagTypeKindForKeyword(ElaboratedTypeKeyword Keyword);
3980
3981  static bool KeywordIsTagTypeKind(ElaboratedTypeKeyword Keyword);
3982
3983  static const char *getKeywordName(ElaboratedTypeKeyword Keyword);
3984
3985  static const char *getTagTypeKindName(TagTypeKind Kind) {
3986    return getKeywordName(getKeywordForTagTypeKind(Kind));
3987  }
3988
3989  class CannotCastToThisType {};
3990  static CannotCastToThisType classof(const Type *);
3991};
3992
3993/// \brief Represents a type that was referred to using an elaborated type
3994/// keyword, e.g., struct S, or via a qualified name, e.g., N::M::type,
3995/// or both.
3996///
3997/// This type is used to keep track of a type name as written in the
3998/// source code, including tag keywords and any nested-name-specifiers.
3999/// The type itself is always "sugar", used to express what was written
4000/// in the source code but containing no additional semantic information.
4001class ElaboratedType : public TypeWithKeyword, public llvm::FoldingSetNode {
4002
4003  /// \brief The nested name specifier containing the qualifier.
4004  NestedNameSpecifier *NNS;
4005
4006  /// \brief The type that this qualified name refers to.
4007  QualType NamedType;
4008
4009  ElaboratedType(ElaboratedTypeKeyword Keyword, NestedNameSpecifier *NNS,
4010                 QualType NamedType, QualType CanonType)
4011    : TypeWithKeyword(Keyword, Elaborated, CanonType,
4012                      NamedType->isDependentType(),
4013                      NamedType->isInstantiationDependentType(),
4014                      NamedType->isVariablyModifiedType(),
4015                      NamedType->containsUnexpandedParameterPack()),
4016      NNS(NNS), NamedType(NamedType) {
4017    assert(!(Keyword == ETK_None && NNS == 0) &&
4018           "ElaboratedType cannot have elaborated type keyword "
4019           "and name qualifier both null.");
4020  }
4021
4022  friend class ASTContext;  // ASTContext creates these
4023
4024public:
4025  ~ElaboratedType();
4026
4027  /// \brief Retrieve the qualification on this type.
4028  NestedNameSpecifier *getQualifier() const { return NNS; }
4029
4030  /// \brief Retrieve the type named by the qualified-id.
4031  QualType getNamedType() const { return NamedType; }
4032
4033  /// \brief Remove a single level of sugar.
4034  QualType desugar() const { return getNamedType(); }
4035
4036  /// \brief Returns whether this type directly provides sugar.
4037  bool isSugared() const { return true; }
4038
4039  void Profile(llvm::FoldingSetNodeID &ID) {
4040    Profile(ID, getKeyword(), NNS, NamedType);
4041  }
4042
4043  static void Profile(llvm::FoldingSetNodeID &ID, ElaboratedTypeKeyword Keyword,
4044                      NestedNameSpecifier *NNS, QualType NamedType) {
4045    ID.AddInteger(Keyword);
4046    ID.AddPointer(NNS);
4047    NamedType.Profile(ID);
4048  }
4049
4050  static bool classof(const Type *T) {
4051    return T->getTypeClass() == Elaborated;
4052  }
4053};
4054
4055/// \brief Represents a qualified type name for which the type name is
4056/// dependent.
4057///
4058/// DependentNameType represents a class of dependent types that involve a
4059/// dependent nested-name-specifier (e.g., "T::") followed by a (dependent)
4060/// name of a type. The DependentNameType may start with a "typename" (for a
4061/// typename-specifier), "class", "struct", "union", or "enum" (for a
4062/// dependent elaborated-type-specifier), or nothing (in contexts where we
4063/// know that we must be referring to a type, e.g., in a base class specifier).
4064class DependentNameType : public TypeWithKeyword, public llvm::FoldingSetNode {
4065
4066  /// \brief The nested name specifier containing the qualifier.
4067  NestedNameSpecifier *NNS;
4068
4069  /// \brief The type that this typename specifier refers to.
4070  const IdentifierInfo *Name;
4071
4072  DependentNameType(ElaboratedTypeKeyword Keyword, NestedNameSpecifier *NNS,
4073                    const IdentifierInfo *Name, QualType CanonType)
4074    : TypeWithKeyword(Keyword, DependentName, CanonType, /*Dependent=*/true,
4075                      /*InstantiationDependent=*/true,
4076                      /*VariablyModified=*/false,
4077                      NNS->containsUnexpandedParameterPack()),
4078      NNS(NNS), Name(Name) {
4079    assert(NNS->isDependent() &&
4080           "DependentNameType requires a dependent nested-name-specifier");
4081  }
4082
4083  friend class ASTContext;  // ASTContext creates these
4084
4085public:
4086  /// \brief Retrieve the qualification on this type.
4087  NestedNameSpecifier *getQualifier() const { return NNS; }
4088
4089  /// \brief Retrieve the type named by the typename specifier as an
4090  /// identifier.
4091  ///
4092  /// This routine will return a non-NULL identifier pointer when the
4093  /// form of the original typename was terminated by an identifier,
4094  /// e.g., "typename T::type".
4095  const IdentifierInfo *getIdentifier() const {
4096    return Name;
4097  }
4098
4099  bool isSugared() const { return false; }
4100  QualType desugar() const { return QualType(this, 0); }
4101
4102  void Profile(llvm::FoldingSetNodeID &ID) {
4103    Profile(ID, getKeyword(), NNS, Name);
4104  }
4105
4106  static void Profile(llvm::FoldingSetNodeID &ID, ElaboratedTypeKeyword Keyword,
4107                      NestedNameSpecifier *NNS, const IdentifierInfo *Name) {
4108    ID.AddInteger(Keyword);
4109    ID.AddPointer(NNS);
4110    ID.AddPointer(Name);
4111  }
4112
4113  static bool classof(const Type *T) {
4114    return T->getTypeClass() == DependentName;
4115  }
4116};
4117
4118/// DependentTemplateSpecializationType - Represents a template
4119/// specialization type whose template cannot be resolved, e.g.
4120///   A<T>::template B<T>
4121class DependentTemplateSpecializationType :
4122  public TypeWithKeyword, public llvm::FoldingSetNode {
4123
4124  /// \brief The nested name specifier containing the qualifier.
4125  NestedNameSpecifier *NNS;
4126
4127  /// \brief The identifier of the template.
4128  const IdentifierInfo *Name;
4129
4130  /// \brief - The number of template arguments named in this class
4131  /// template specialization.
4132  unsigned NumArgs;
4133
4134  const TemplateArgument *getArgBuffer() const {
4135    return reinterpret_cast<const TemplateArgument*>(this+1);
4136  }
4137  TemplateArgument *getArgBuffer() {
4138    return reinterpret_cast<TemplateArgument*>(this+1);
4139  }
4140
4141  DependentTemplateSpecializationType(ElaboratedTypeKeyword Keyword,
4142                                      NestedNameSpecifier *NNS,
4143                                      const IdentifierInfo *Name,
4144                                      unsigned NumArgs,
4145                                      const TemplateArgument *Args,
4146                                      QualType Canon);
4147
4148  friend class ASTContext;  // ASTContext creates these
4149
4150public:
4151  NestedNameSpecifier *getQualifier() const { return NNS; }
4152  const IdentifierInfo *getIdentifier() const { return Name; }
4153
4154  /// \brief Retrieve the template arguments.
4155  const TemplateArgument *getArgs() const {
4156    return getArgBuffer();
4157  }
4158
4159  /// \brief Retrieve the number of template arguments.
4160  unsigned getNumArgs() const { return NumArgs; }
4161
4162  const TemplateArgument &getArg(unsigned Idx) const; // in TemplateBase.h
4163
4164  typedef const TemplateArgument * iterator;
4165  iterator begin() const { return getArgs(); }
4166  iterator end() const; // inline in TemplateBase.h
4167
4168  bool isSugared() const { return false; }
4169  QualType desugar() const { return QualType(this, 0); }
4170
4171  void Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Context) {
4172    Profile(ID, Context, getKeyword(), NNS, Name, NumArgs, getArgs());
4173  }
4174
4175  static void Profile(llvm::FoldingSetNodeID &ID,
4176                      const ASTContext &Context,
4177                      ElaboratedTypeKeyword Keyword,
4178                      NestedNameSpecifier *Qualifier,
4179                      const IdentifierInfo *Name,
4180                      unsigned NumArgs,
4181                      const TemplateArgument *Args);
4182
4183  static bool classof(const Type *T) {
4184    return T->getTypeClass() == DependentTemplateSpecialization;
4185  }
4186};
4187
4188/// \brief Represents a pack expansion of types.
4189///
4190/// Pack expansions are part of C++0x variadic templates. A pack
4191/// expansion contains a pattern, which itself contains one or more
4192/// "unexpanded" parameter packs. When instantiated, a pack expansion
4193/// produces a series of types, each instantiated from the pattern of
4194/// the expansion, where the Ith instantiation of the pattern uses the
4195/// Ith arguments bound to each of the unexpanded parameter packs. The
4196/// pack expansion is considered to "expand" these unexpanded
4197/// parameter packs.
4198///
4199/// \code
4200/// template<typename ...Types> struct tuple;
4201///
4202/// template<typename ...Types>
4203/// struct tuple_of_references {
4204///   typedef tuple<Types&...> type;
4205/// };
4206/// \endcode
4207///
4208/// Here, the pack expansion \c Types&... is represented via a
4209/// PackExpansionType whose pattern is Types&.
4210class PackExpansionType : public Type, public llvm::FoldingSetNode {
4211  /// \brief The pattern of the pack expansion.
4212  QualType Pattern;
4213
4214  /// \brief The number of expansions that this pack expansion will
4215  /// generate when substituted (+1), or indicates that
4216  ///
4217  /// This field will only have a non-zero value when some of the parameter
4218  /// packs that occur within the pattern have been substituted but others have
4219  /// not.
4220  unsigned NumExpansions;
4221
4222  PackExpansionType(QualType Pattern, QualType Canon,
4223                    Optional<unsigned> NumExpansions)
4224    : Type(PackExpansion, Canon, /*Dependent=*/Pattern->isDependentType(),
4225           /*InstantiationDependent=*/true,
4226           /*VariableModified=*/Pattern->isVariablyModifiedType(),
4227           /*ContainsUnexpandedParameterPack=*/false),
4228      Pattern(Pattern),
4229      NumExpansions(NumExpansions? *NumExpansions + 1: 0) { }
4230
4231  friend class ASTContext;  // ASTContext creates these
4232
4233public:
4234  /// \brief Retrieve the pattern of this pack expansion, which is the
4235  /// type that will be repeatedly instantiated when instantiating the
4236  /// pack expansion itself.
4237  QualType getPattern() const { return Pattern; }
4238
4239  /// \brief Retrieve the number of expansions that this pack expansion will
4240  /// generate, if known.
4241  Optional<unsigned> getNumExpansions() const {
4242    if (NumExpansions)
4243      return NumExpansions - 1;
4244
4245    return None;
4246  }
4247
4248  bool isSugared() const { return !Pattern->isDependentType(); }
4249  QualType desugar() const { return isSugared() ? Pattern : QualType(this, 0); }
4250
4251  void Profile(llvm::FoldingSetNodeID &ID) {
4252    Profile(ID, getPattern(), getNumExpansions());
4253  }
4254
4255  static void Profile(llvm::FoldingSetNodeID &ID, QualType Pattern,
4256                      Optional<unsigned> NumExpansions) {
4257    ID.AddPointer(Pattern.getAsOpaquePtr());
4258    ID.AddBoolean(NumExpansions.hasValue());
4259    if (NumExpansions)
4260      ID.AddInteger(*NumExpansions);
4261  }
4262
4263  static bool classof(const Type *T) {
4264    return T->getTypeClass() == PackExpansion;
4265  }
4266};
4267
4268/// ObjCObjectType - Represents a class type in Objective C.
4269/// Every Objective C type is a combination of a base type and a
4270/// list of protocols.
4271///
4272/// Given the following declarations:
4273/// \code
4274///   \@class C;
4275///   \@protocol P;
4276/// \endcode
4277///
4278/// 'C' is an ObjCInterfaceType C.  It is sugar for an ObjCObjectType
4279/// with base C and no protocols.
4280///
4281/// 'C<P>' is an ObjCObjectType with base C and protocol list [P].
4282///
4283/// 'id' is a TypedefType which is sugar for an ObjCObjectPointerType whose
4284/// pointee is an ObjCObjectType with base BuiltinType::ObjCIdType
4285/// and no protocols.
4286///
4287/// 'id<P>' is an ObjCObjectPointerType whose pointee is an ObjCObjectType
4288/// with base BuiltinType::ObjCIdType and protocol list [P].  Eventually
4289/// this should get its own sugar class to better represent the source.
4290class ObjCObjectType : public Type {
4291  // ObjCObjectType.NumProtocols - the number of protocols stored
4292  // after the ObjCObjectPointerType node.
4293  //
4294  // These protocols are those written directly on the type.  If
4295  // protocol qualifiers ever become additive, the iterators will need
4296  // to get kindof complicated.
4297  //
4298  // In the canonical object type, these are sorted alphabetically
4299  // and uniqued.
4300
4301  /// Either a BuiltinType or an InterfaceType or sugar for either.
4302  QualType BaseType;
4303
4304  ObjCProtocolDecl * const *getProtocolStorage() const {
4305    return const_cast<ObjCObjectType*>(this)->getProtocolStorage();
4306  }
4307
4308  ObjCProtocolDecl **getProtocolStorage();
4309
4310protected:
4311  ObjCObjectType(QualType Canonical, QualType Base,
4312                 ObjCProtocolDecl * const *Protocols, unsigned NumProtocols);
4313
4314  enum Nonce_ObjCInterface { Nonce_ObjCInterface };
4315  ObjCObjectType(enum Nonce_ObjCInterface)
4316        : Type(ObjCInterface, QualType(), false, false, false, false),
4317      BaseType(QualType(this_(), 0)) {
4318    ObjCObjectTypeBits.NumProtocols = 0;
4319  }
4320
4321public:
4322  /// getBaseType - Gets the base type of this object type.  This is
4323  /// always (possibly sugar for) one of:
4324  ///  - the 'id' builtin type (as opposed to the 'id' type visible to the
4325  ///    user, which is a typedef for an ObjCObjectPointerType)
4326  ///  - the 'Class' builtin type (same caveat)
4327  ///  - an ObjCObjectType (currently always an ObjCInterfaceType)
4328  QualType getBaseType() const { return BaseType; }
4329
4330  bool isObjCId() const {
4331    return getBaseType()->isSpecificBuiltinType(BuiltinType::ObjCId);
4332  }
4333  bool isObjCClass() const {
4334    return getBaseType()->isSpecificBuiltinType(BuiltinType::ObjCClass);
4335  }
4336  bool isObjCUnqualifiedId() const { return qual_empty() && isObjCId(); }
4337  bool isObjCUnqualifiedClass() const { return qual_empty() && isObjCClass(); }
4338  bool isObjCUnqualifiedIdOrClass() const {
4339    if (!qual_empty()) return false;
4340    if (const BuiltinType *T = getBaseType()->getAs<BuiltinType>())
4341      return T->getKind() == BuiltinType::ObjCId ||
4342             T->getKind() == BuiltinType::ObjCClass;
4343    return false;
4344  }
4345  bool isObjCQualifiedId() const { return !qual_empty() && isObjCId(); }
4346  bool isObjCQualifiedClass() const { return !qual_empty() && isObjCClass(); }
4347
4348  /// Gets the interface declaration for this object type, if the base type
4349  /// really is an interface.
4350  ObjCInterfaceDecl *getInterface() const;
4351
4352  typedef ObjCProtocolDecl * const *qual_iterator;
4353  typedef llvm::iterator_range<qual_iterator> qual_range;
4354
4355  qual_range quals() const { return qual_range(qual_begin(), qual_end()); }
4356  qual_iterator qual_begin() const { return getProtocolStorage(); }
4357  qual_iterator qual_end() const { return qual_begin() + getNumProtocols(); }
4358
4359  bool qual_empty() const { return getNumProtocols() == 0; }
4360
4361  /// getNumProtocols - Return the number of qualifying protocols in this
4362  /// interface type, or 0 if there are none.
4363  unsigned getNumProtocols() const { return ObjCObjectTypeBits.NumProtocols; }
4364
4365  /// \brief Fetch a protocol by index.
4366  ObjCProtocolDecl *getProtocol(unsigned I) const {
4367    assert(I < getNumProtocols() && "Out-of-range protocol access");
4368    return qual_begin()[I];
4369  }
4370
4371  bool isSugared() const { return false; }
4372  QualType desugar() const { return QualType(this, 0); }
4373
4374  static bool classof(const Type *T) {
4375    return T->getTypeClass() == ObjCObject ||
4376           T->getTypeClass() == ObjCInterface;
4377  }
4378};
4379
4380/// ObjCObjectTypeImpl - A class providing a concrete implementation
4381/// of ObjCObjectType, so as to not increase the footprint of
4382/// ObjCInterfaceType.  Code outside of ASTContext and the core type
4383/// system should not reference this type.
4384class ObjCObjectTypeImpl : public ObjCObjectType, public llvm::FoldingSetNode {
4385  friend class ASTContext;
4386
4387  // If anyone adds fields here, ObjCObjectType::getProtocolStorage()
4388  // will need to be modified.
4389
4390  ObjCObjectTypeImpl(QualType Canonical, QualType Base,
4391                     ObjCProtocolDecl * const *Protocols,
4392                     unsigned NumProtocols)
4393    : ObjCObjectType(Canonical, Base, Protocols, NumProtocols) {}
4394
4395public:
4396  void Profile(llvm::FoldingSetNodeID &ID);
4397  static void Profile(llvm::FoldingSetNodeID &ID,
4398                      QualType Base,
4399                      ObjCProtocolDecl *const *protocols,
4400                      unsigned NumProtocols);
4401};
4402
4403inline ObjCProtocolDecl **ObjCObjectType::getProtocolStorage() {
4404  return reinterpret_cast<ObjCProtocolDecl**>(
4405            static_cast<ObjCObjectTypeImpl*>(this) + 1);
4406}
4407
4408/// ObjCInterfaceType - Interfaces are the core concept in Objective-C for
4409/// object oriented design.  They basically correspond to C++ classes.  There
4410/// are two kinds of interface types, normal interfaces like "NSString" and
4411/// qualified interfaces, which are qualified with a protocol list like
4412/// "NSString<NSCopyable, NSAmazing>".
4413///
4414/// ObjCInterfaceType guarantees the following properties when considered
4415/// as a subtype of its superclass, ObjCObjectType:
4416///   - There are no protocol qualifiers.  To reinforce this, code which
4417///     tries to invoke the protocol methods via an ObjCInterfaceType will
4418///     fail to compile.
4419///   - It is its own base type.  That is, if T is an ObjCInterfaceType*,
4420///     T->getBaseType() == QualType(T, 0).
4421class ObjCInterfaceType : public ObjCObjectType {
4422  mutable ObjCInterfaceDecl *Decl;
4423
4424  ObjCInterfaceType(const ObjCInterfaceDecl *D)
4425    : ObjCObjectType(Nonce_ObjCInterface),
4426      Decl(const_cast<ObjCInterfaceDecl*>(D)) {}
4427  friend class ASTContext;  // ASTContext creates these.
4428  friend class ASTReader;
4429  friend class ObjCInterfaceDecl;
4430
4431public:
4432  /// getDecl - Get the declaration of this interface.
4433  ObjCInterfaceDecl *getDecl() const { return Decl; }
4434
4435  bool isSugared() const { return false; }
4436  QualType desugar() const { return QualType(this, 0); }
4437
4438  static bool classof(const Type *T) {
4439    return T->getTypeClass() == ObjCInterface;
4440  }
4441
4442  // Nonsense to "hide" certain members of ObjCObjectType within this
4443  // class.  People asking for protocols on an ObjCInterfaceType are
4444  // not going to get what they want: ObjCInterfaceTypes are
4445  // guaranteed to have no protocols.
4446  enum {
4447    qual_iterator,
4448    qual_begin,
4449    qual_end,
4450    getNumProtocols,
4451    getProtocol
4452  };
4453};
4454
4455inline ObjCInterfaceDecl *ObjCObjectType::getInterface() const {
4456  if (const ObjCInterfaceType *T =
4457        getBaseType()->getAs<ObjCInterfaceType>())
4458    return T->getDecl();
4459  return 0;
4460}
4461
4462/// ObjCObjectPointerType - Used to represent a pointer to an
4463/// Objective C object.  These are constructed from pointer
4464/// declarators when the pointee type is an ObjCObjectType (or sugar
4465/// for one).  In addition, the 'id' and 'Class' types are typedefs
4466/// for these, and the protocol-qualified types 'id<P>' and 'Class<P>'
4467/// are translated into these.
4468///
4469/// Pointers to pointers to Objective C objects are still PointerTypes;
4470/// only the first level of pointer gets it own type implementation.
4471class ObjCObjectPointerType : public Type, public llvm::FoldingSetNode {
4472  QualType PointeeType;
4473
4474  ObjCObjectPointerType(QualType Canonical, QualType Pointee)
4475    : Type(ObjCObjectPointer, Canonical, false, false, false, false),
4476      PointeeType(Pointee) {}
4477  friend class ASTContext;  // ASTContext creates these.
4478
4479public:
4480  /// getPointeeType - Gets the type pointed to by this ObjC pointer.
4481  /// The result will always be an ObjCObjectType or sugar thereof.
4482  QualType getPointeeType() const { return PointeeType; }
4483
4484  /// getObjCObjectType - Gets the type pointed to by this ObjC
4485  /// pointer.  This method always returns non-null.
4486  ///
4487  /// This method is equivalent to getPointeeType() except that
4488  /// it discards any typedefs (or other sugar) between this
4489  /// type and the "outermost" object type.  So for:
4490  /// \code
4491  ///   \@class A; \@protocol P; \@protocol Q;
4492  ///   typedef A<P> AP;
4493  ///   typedef A A1;
4494  ///   typedef A1<P> A1P;
4495  ///   typedef A1P<Q> A1PQ;
4496  /// \endcode
4497  /// For 'A*', getObjectType() will return 'A'.
4498  /// For 'A<P>*', getObjectType() will return 'A<P>'.
4499  /// For 'AP*', getObjectType() will return 'A<P>'.
4500  /// For 'A1*', getObjectType() will return 'A'.
4501  /// For 'A1<P>*', getObjectType() will return 'A1<P>'.
4502  /// For 'A1P*', getObjectType() will return 'A1<P>'.
4503  /// For 'A1PQ*', getObjectType() will return 'A1<Q>', because
4504  ///   adding protocols to a protocol-qualified base discards the
4505  ///   old qualifiers (for now).  But if it didn't, getObjectType()
4506  ///   would return 'A1P<Q>' (and we'd have to make iterating over
4507  ///   qualifiers more complicated).
4508  const ObjCObjectType *getObjectType() const {
4509    return PointeeType->castAs<ObjCObjectType>();
4510  }
4511
4512  /// getInterfaceType - If this pointer points to an Objective C
4513  /// \@interface type, gets the type for that interface.  Any protocol
4514  /// qualifiers on the interface are ignored.
4515  ///
4516  /// \return null if the base type for this pointer is 'id' or 'Class'
4517  const ObjCInterfaceType *getInterfaceType() const {
4518    return getObjectType()->getBaseType()->getAs<ObjCInterfaceType>();
4519  }
4520
4521  /// getInterfaceDecl - If this pointer points to an Objective \@interface
4522  /// type, gets the declaration for that interface.
4523  ///
4524  /// \return null if the base type for this pointer is 'id' or 'Class'
4525  ObjCInterfaceDecl *getInterfaceDecl() const {
4526    return getObjectType()->getInterface();
4527  }
4528
4529  /// isObjCIdType - True if this is equivalent to the 'id' type, i.e. if
4530  /// its object type is the primitive 'id' type with no protocols.
4531  bool isObjCIdType() const {
4532    return getObjectType()->isObjCUnqualifiedId();
4533  }
4534
4535  /// isObjCClassType - True if this is equivalent to the 'Class' type,
4536  /// i.e. if its object tive is the primitive 'Class' type with no protocols.
4537  bool isObjCClassType() const {
4538    return getObjectType()->isObjCUnqualifiedClass();
4539  }
4540
4541  /// isObjCQualifiedIdType - True if this is equivalent to 'id<P>' for some
4542  /// non-empty set of protocols.
4543  bool isObjCQualifiedIdType() const {
4544    return getObjectType()->isObjCQualifiedId();
4545  }
4546
4547  /// isObjCQualifiedClassType - True if this is equivalent to 'Class<P>' for
4548  /// some non-empty set of protocols.
4549  bool isObjCQualifiedClassType() const {
4550    return getObjectType()->isObjCQualifiedClass();
4551  }
4552
4553  /// An iterator over the qualifiers on the object type.  Provided
4554  /// for convenience.  This will always iterate over the full set of
4555  /// protocols on a type, not just those provided directly.
4556  typedef ObjCObjectType::qual_iterator qual_iterator;
4557  typedef llvm::iterator_range<qual_iterator> qual_range;
4558
4559  qual_range quals() const { return qual_range(qual_begin(), qual_end()); }
4560  qual_iterator qual_begin() const {
4561    return getObjectType()->qual_begin();
4562  }
4563  qual_iterator qual_end() const {
4564    return getObjectType()->qual_end();
4565  }
4566  bool qual_empty() const { return getObjectType()->qual_empty(); }
4567
4568  /// getNumProtocols - Return the number of qualifying protocols on
4569  /// the object type.
4570  unsigned getNumProtocols() const {
4571    return getObjectType()->getNumProtocols();
4572  }
4573
4574  /// \brief Retrieve a qualifying protocol by index on the object
4575  /// type.
4576  ObjCProtocolDecl *getProtocol(unsigned I) const {
4577    return getObjectType()->getProtocol(I);
4578  }
4579
4580  bool isSugared() const { return false; }
4581  QualType desugar() const { return QualType(this, 0); }
4582
4583  void Profile(llvm::FoldingSetNodeID &ID) {
4584    Profile(ID, getPointeeType());
4585  }
4586  static void Profile(llvm::FoldingSetNodeID &ID, QualType T) {
4587    ID.AddPointer(T.getAsOpaquePtr());
4588  }
4589  static bool classof(const Type *T) {
4590    return T->getTypeClass() == ObjCObjectPointer;
4591  }
4592};
4593
4594class AtomicType : public Type, public llvm::FoldingSetNode {
4595  QualType ValueType;
4596
4597  AtomicType(QualType ValTy, QualType Canonical)
4598    : Type(Atomic, Canonical, ValTy->isDependentType(),
4599           ValTy->isInstantiationDependentType(),
4600           ValTy->isVariablyModifiedType(),
4601           ValTy->containsUnexpandedParameterPack()),
4602      ValueType(ValTy) {}
4603  friend class ASTContext;  // ASTContext creates these.
4604
4605  public:
4606  /// getValueType - Gets the type contained by this atomic type, i.e.
4607  /// the type returned by performing an atomic load of this atomic type.
4608  QualType getValueType() const { return ValueType; }
4609
4610  bool isSugared() const { return false; }
4611  QualType desugar() const { return QualType(this, 0); }
4612
4613  void Profile(llvm::FoldingSetNodeID &ID) {
4614    Profile(ID, getValueType());
4615  }
4616  static void Profile(llvm::FoldingSetNodeID &ID, QualType T) {
4617    ID.AddPointer(T.getAsOpaquePtr());
4618  }
4619  static bool classof(const Type *T) {
4620    return T->getTypeClass() == Atomic;
4621  }
4622};
4623
4624/// A qualifier set is used to build a set of qualifiers.
4625class QualifierCollector : public Qualifiers {
4626public:
4627  QualifierCollector(Qualifiers Qs = Qualifiers()) : Qualifiers(Qs) {}
4628
4629  /// Collect any qualifiers on the given type and return an
4630  /// unqualified type.  The qualifiers are assumed to be consistent
4631  /// with those already in the type.
4632  const Type *strip(QualType type) {
4633    addFastQualifiers(type.getLocalFastQualifiers());
4634    if (!type.hasLocalNonFastQualifiers())
4635      return type.getTypePtrUnsafe();
4636
4637    const ExtQuals *extQuals = type.getExtQualsUnsafe();
4638    addConsistentQualifiers(extQuals->getQualifiers());
4639    return extQuals->getBaseType();
4640  }
4641
4642  /// Apply the collected qualifiers to the given type.
4643  QualType apply(const ASTContext &Context, QualType QT) const;
4644
4645  /// Apply the collected qualifiers to the given type.
4646  QualType apply(const ASTContext &Context, const Type* T) const;
4647};
4648
4649
4650// Inline function definitions.
4651
4652inline SplitQualType SplitQualType::getSingleStepDesugaredType() const {
4653  SplitQualType desugar =
4654    Ty->getLocallyUnqualifiedSingleStepDesugaredType().split();
4655  desugar.Quals.addConsistentQualifiers(Quals);
4656  return desugar;
4657}
4658
4659inline const Type *QualType::getTypePtr() const {
4660  return getCommonPtr()->BaseType;
4661}
4662
4663inline const Type *QualType::getTypePtrOrNull() const {
4664  return (isNull() ? 0 : getCommonPtr()->BaseType);
4665}
4666
4667inline SplitQualType QualType::split() const {
4668  if (!hasLocalNonFastQualifiers())
4669    return SplitQualType(getTypePtrUnsafe(),
4670                         Qualifiers::fromFastMask(getLocalFastQualifiers()));
4671
4672  const ExtQuals *eq = getExtQualsUnsafe();
4673  Qualifiers qs = eq->getQualifiers();
4674  qs.addFastQualifiers(getLocalFastQualifiers());
4675  return SplitQualType(eq->getBaseType(), qs);
4676}
4677
4678inline Qualifiers QualType::getLocalQualifiers() const {
4679  Qualifiers Quals;
4680  if (hasLocalNonFastQualifiers())
4681    Quals = getExtQualsUnsafe()->getQualifiers();
4682  Quals.addFastQualifiers(getLocalFastQualifiers());
4683  return Quals;
4684}
4685
4686inline Qualifiers QualType::getQualifiers() const {
4687  Qualifiers quals = getCommonPtr()->CanonicalType.getLocalQualifiers();
4688  quals.addFastQualifiers(getLocalFastQualifiers());
4689  return quals;
4690}
4691
4692inline unsigned QualType::getCVRQualifiers() const {
4693  unsigned cvr = getCommonPtr()->CanonicalType.getLocalCVRQualifiers();
4694  cvr |= getLocalCVRQualifiers();
4695  return cvr;
4696}
4697
4698inline QualType QualType::getCanonicalType() const {
4699  QualType canon = getCommonPtr()->CanonicalType;
4700  return canon.withFastQualifiers(getLocalFastQualifiers());
4701}
4702
4703inline bool QualType::isCanonical() const {
4704  return getTypePtr()->isCanonicalUnqualified();
4705}
4706
4707inline bool QualType::isCanonicalAsParam() const {
4708  if (!isCanonical()) return false;
4709  if (hasLocalQualifiers()) return false;
4710
4711  const Type *T = getTypePtr();
4712  if (T->isVariablyModifiedType() && T->hasSizedVLAType())
4713    return false;
4714
4715  return !isa<FunctionType>(T) && !isa<ArrayType>(T);
4716}
4717
4718inline bool QualType::isConstQualified() const {
4719  return isLocalConstQualified() ||
4720         getCommonPtr()->CanonicalType.isLocalConstQualified();
4721}
4722
4723inline bool QualType::isRestrictQualified() const {
4724  return isLocalRestrictQualified() ||
4725         getCommonPtr()->CanonicalType.isLocalRestrictQualified();
4726}
4727
4728
4729inline bool QualType::isVolatileQualified() const {
4730  return isLocalVolatileQualified() ||
4731         getCommonPtr()->CanonicalType.isLocalVolatileQualified();
4732}
4733
4734inline bool QualType::hasQualifiers() const {
4735  return hasLocalQualifiers() ||
4736         getCommonPtr()->CanonicalType.hasLocalQualifiers();
4737}
4738
4739inline QualType QualType::getUnqualifiedType() const {
4740  if (!getTypePtr()->getCanonicalTypeInternal().hasLocalQualifiers())
4741    return QualType(getTypePtr(), 0);
4742
4743  return QualType(getSplitUnqualifiedTypeImpl(*this).Ty, 0);
4744}
4745
4746inline SplitQualType QualType::getSplitUnqualifiedType() const {
4747  if (!getTypePtr()->getCanonicalTypeInternal().hasLocalQualifiers())
4748    return split();
4749
4750  return getSplitUnqualifiedTypeImpl(*this);
4751}
4752
4753inline void QualType::removeLocalConst() {
4754  removeLocalFastQualifiers(Qualifiers::Const);
4755}
4756
4757inline void QualType::removeLocalRestrict() {
4758  removeLocalFastQualifiers(Qualifiers::Restrict);
4759}
4760
4761inline void QualType::removeLocalVolatile() {
4762  removeLocalFastQualifiers(Qualifiers::Volatile);
4763}
4764
4765inline void QualType::removeLocalCVRQualifiers(unsigned Mask) {
4766  assert(!(Mask & ~Qualifiers::CVRMask) && "mask has non-CVR bits");
4767  assert((int)Qualifiers::CVRMask == (int)Qualifiers::FastMask);
4768
4769  // Fast path: we don't need to touch the slow qualifiers.
4770  removeLocalFastQualifiers(Mask);
4771}
4772
4773/// getAddressSpace - Return the address space of this type.
4774inline unsigned QualType::getAddressSpace() const {
4775  return getQualifiers().getAddressSpace();
4776}
4777
4778/// getObjCGCAttr - Return the gc attribute of this type.
4779inline Qualifiers::GC QualType::getObjCGCAttr() const {
4780  return getQualifiers().getObjCGCAttr();
4781}
4782
4783inline FunctionType::ExtInfo getFunctionExtInfo(const Type &t) {
4784  if (const PointerType *PT = t.getAs<PointerType>()) {
4785    if (const FunctionType *FT = PT->getPointeeType()->getAs<FunctionType>())
4786      return FT->getExtInfo();
4787  } else if (const FunctionType *FT = t.getAs<FunctionType>())
4788    return FT->getExtInfo();
4789
4790  return FunctionType::ExtInfo();
4791}
4792
4793inline FunctionType::ExtInfo getFunctionExtInfo(QualType t) {
4794  return getFunctionExtInfo(*t);
4795}
4796
4797/// isMoreQualifiedThan - Determine whether this type is more
4798/// qualified than the Other type. For example, "const volatile int"
4799/// is more qualified than "const int", "volatile int", and
4800/// "int". However, it is not more qualified than "const volatile
4801/// int".
4802inline bool QualType::isMoreQualifiedThan(QualType other) const {
4803  Qualifiers myQuals = getQualifiers();
4804  Qualifiers otherQuals = other.getQualifiers();
4805  return (myQuals != otherQuals && myQuals.compatiblyIncludes(otherQuals));
4806}
4807
4808/// isAtLeastAsQualifiedAs - Determine whether this type is at last
4809/// as qualified as the Other type. For example, "const volatile
4810/// int" is at least as qualified as "const int", "volatile int",
4811/// "int", and "const volatile int".
4812inline bool QualType::isAtLeastAsQualifiedAs(QualType other) const {
4813  return getQualifiers().compatiblyIncludes(other.getQualifiers());
4814}
4815
4816/// getNonReferenceType - If Type is a reference type (e.g., const
4817/// int&), returns the type that the reference refers to ("const
4818/// int"). Otherwise, returns the type itself. This routine is used
4819/// throughout Sema to implement C++ 5p6:
4820///
4821///   If an expression initially has the type "reference to T" (8.3.2,
4822///   8.5.3), the type is adjusted to "T" prior to any further
4823///   analysis, the expression designates the object or function
4824///   denoted by the reference, and the expression is an lvalue.
4825inline QualType QualType::getNonReferenceType() const {
4826  if (const ReferenceType *RefType = (*this)->getAs<ReferenceType>())
4827    return RefType->getPointeeType();
4828  else
4829    return *this;
4830}
4831
4832inline bool QualType::isCForbiddenLValueType() const {
4833  return ((getTypePtr()->isVoidType() && !hasQualifiers()) ||
4834          getTypePtr()->isFunctionType());
4835}
4836
4837/// \brief Tests whether the type is categorized as a fundamental type.
4838///
4839/// \returns True for types specified in C++0x [basic.fundamental].
4840inline bool Type::isFundamentalType() const {
4841  return isVoidType() ||
4842         // FIXME: It's really annoying that we don't have an
4843         // 'isArithmeticType()' which agrees with the standard definition.
4844         (isArithmeticType() && !isEnumeralType());
4845}
4846
4847/// \brief Tests whether the type is categorized as a compound type.
4848///
4849/// \returns True for types specified in C++0x [basic.compound].
4850inline bool Type::isCompoundType() const {
4851  // C++0x [basic.compound]p1:
4852  //   Compound types can be constructed in the following ways:
4853  //    -- arrays of objects of a given type [...];
4854  return isArrayType() ||
4855  //    -- functions, which have parameters of given types [...];
4856         isFunctionType() ||
4857  //    -- pointers to void or objects or functions [...];
4858         isPointerType() ||
4859  //    -- references to objects or functions of a given type. [...]
4860         isReferenceType() ||
4861  //    -- classes containing a sequence of objects of various types, [...];
4862         isRecordType() ||
4863  //    -- unions, which are classes capable of containing objects of different
4864  //               types at different times;
4865         isUnionType() ||
4866  //    -- enumerations, which comprise a set of named constant values. [...];
4867         isEnumeralType() ||
4868  //    -- pointers to non-static class members, [...].
4869         isMemberPointerType();
4870}
4871
4872inline bool Type::isFunctionType() const {
4873  return isa<FunctionType>(CanonicalType);
4874}
4875inline bool Type::isPointerType() const {
4876  return isa<PointerType>(CanonicalType);
4877}
4878inline bool Type::isAnyPointerType() const {
4879  return isPointerType() || isObjCObjectPointerType();
4880}
4881inline bool Type::isBlockPointerType() const {
4882  return isa<BlockPointerType>(CanonicalType);
4883}
4884inline bool Type::isReferenceType() const {
4885  return isa<ReferenceType>(CanonicalType);
4886}
4887inline bool Type::isLValueReferenceType() const {
4888  return isa<LValueReferenceType>(CanonicalType);
4889}
4890inline bool Type::isRValueReferenceType() const {
4891  return isa<RValueReferenceType>(CanonicalType);
4892}
4893inline bool Type::isFunctionPointerType() const {
4894  if (const PointerType *T = getAs<PointerType>())
4895    return T->getPointeeType()->isFunctionType();
4896  else
4897    return false;
4898}
4899inline bool Type::isMemberPointerType() const {
4900  return isa<MemberPointerType>(CanonicalType);
4901}
4902inline bool Type::isMemberFunctionPointerType() const {
4903  if (const MemberPointerType* T = getAs<MemberPointerType>())
4904    return T->isMemberFunctionPointer();
4905  else
4906    return false;
4907}
4908inline bool Type::isMemberDataPointerType() const {
4909  if (const MemberPointerType* T = getAs<MemberPointerType>())
4910    return T->isMemberDataPointer();
4911  else
4912    return false;
4913}
4914inline bool Type::isArrayType() const {
4915  return isa<ArrayType>(CanonicalType);
4916}
4917inline bool Type::isConstantArrayType() const {
4918  return isa<ConstantArrayType>(CanonicalType);
4919}
4920inline bool Type::isIncompleteArrayType() const {
4921  return isa<IncompleteArrayType>(CanonicalType);
4922}
4923inline bool Type::isVariableArrayType() const {
4924  return isa<VariableArrayType>(CanonicalType);
4925}
4926inline bool Type::isDependentSizedArrayType() const {
4927  return isa<DependentSizedArrayType>(CanonicalType);
4928}
4929inline bool Type::isBuiltinType() const {
4930  return isa<BuiltinType>(CanonicalType);
4931}
4932inline bool Type::isRecordType() const {
4933  return isa<RecordType>(CanonicalType);
4934}
4935inline bool Type::isEnumeralType() const {
4936  return isa<EnumType>(CanonicalType);
4937}
4938inline bool Type::isAnyComplexType() const {
4939  return isa<ComplexType>(CanonicalType);
4940}
4941inline bool Type::isVectorType() const {
4942  return isa<VectorType>(CanonicalType);
4943}
4944inline bool Type::isExtVectorType() const {
4945  return isa<ExtVectorType>(CanonicalType);
4946}
4947inline bool Type::isObjCObjectPointerType() const {
4948  return isa<ObjCObjectPointerType>(CanonicalType);
4949}
4950inline bool Type::isObjCObjectType() const {
4951  return isa<ObjCObjectType>(CanonicalType);
4952}
4953inline bool Type::isObjCObjectOrInterfaceType() const {
4954  return isa<ObjCInterfaceType>(CanonicalType) ||
4955    isa<ObjCObjectType>(CanonicalType);
4956}
4957inline bool Type::isAtomicType() const {
4958  return isa<AtomicType>(CanonicalType);
4959}
4960
4961inline bool Type::isObjCQualifiedIdType() const {
4962  if (const ObjCObjectPointerType *OPT = getAs<ObjCObjectPointerType>())
4963    return OPT->isObjCQualifiedIdType();
4964  return false;
4965}
4966inline bool Type::isObjCQualifiedClassType() const {
4967  if (const ObjCObjectPointerType *OPT = getAs<ObjCObjectPointerType>())
4968    return OPT->isObjCQualifiedClassType();
4969  return false;
4970}
4971inline bool Type::isObjCIdType() const {
4972  if (const ObjCObjectPointerType *OPT = getAs<ObjCObjectPointerType>())
4973    return OPT->isObjCIdType();
4974  return false;
4975}
4976inline bool Type::isObjCClassType() const {
4977  if (const ObjCObjectPointerType *OPT = getAs<ObjCObjectPointerType>())
4978    return OPT->isObjCClassType();
4979  return false;
4980}
4981inline bool Type::isObjCSelType() const {
4982  if (const PointerType *OPT = getAs<PointerType>())
4983    return OPT->getPointeeType()->isSpecificBuiltinType(BuiltinType::ObjCSel);
4984  return false;
4985}
4986inline bool Type::isObjCBuiltinType() const {
4987  return isObjCIdType() || isObjCClassType() || isObjCSelType();
4988}
4989
4990inline bool Type::isImage1dT() const {
4991  return isSpecificBuiltinType(BuiltinType::OCLImage1d);
4992}
4993
4994inline bool Type::isImage1dArrayT() const {
4995  return isSpecificBuiltinType(BuiltinType::OCLImage1dArray);
4996}
4997
4998inline bool Type::isImage1dBufferT() const {
4999  return isSpecificBuiltinType(BuiltinType::OCLImage1dBuffer);
5000}
5001
5002inline bool Type::isImage2dT() const {
5003  return isSpecificBuiltinType(BuiltinType::OCLImage2d);
5004}
5005
5006inline bool Type::isImage2dArrayT() const {
5007  return isSpecificBuiltinType(BuiltinType::OCLImage2dArray);
5008}
5009
5010inline bool Type::isImage3dT() const {
5011  return isSpecificBuiltinType(BuiltinType::OCLImage3d);
5012}
5013
5014inline bool Type::isSamplerT() const {
5015  return isSpecificBuiltinType(BuiltinType::OCLSampler);
5016}
5017
5018inline bool Type::isEventT() const {
5019  return isSpecificBuiltinType(BuiltinType::OCLEvent);
5020}
5021
5022inline bool Type::isImageType() const {
5023  return isImage3dT() ||
5024         isImage2dT() || isImage2dArrayT() ||
5025         isImage1dT() || isImage1dArrayT() || isImage1dBufferT();
5026}
5027
5028inline bool Type::isOpenCLSpecificType() const {
5029  return isSamplerT() || isEventT() || isImageType();
5030}
5031
5032inline bool Type::isTemplateTypeParmType() const {
5033  return isa<TemplateTypeParmType>(CanonicalType);
5034}
5035
5036inline bool Type::isSpecificBuiltinType(unsigned K) const {
5037  if (const BuiltinType *BT = getAs<BuiltinType>())
5038    if (BT->getKind() == (BuiltinType::Kind) K)
5039      return true;
5040  return false;
5041}
5042
5043inline bool Type::isPlaceholderType() const {
5044  if (const BuiltinType *BT = dyn_cast<BuiltinType>(this))
5045    return BT->isPlaceholderType();
5046  return false;
5047}
5048
5049inline const BuiltinType *Type::getAsPlaceholderType() const {
5050  if (const BuiltinType *BT = dyn_cast<BuiltinType>(this))
5051    if (BT->isPlaceholderType())
5052      return BT;
5053  return 0;
5054}
5055
5056inline bool Type::isSpecificPlaceholderType(unsigned K) const {
5057  assert(BuiltinType::isPlaceholderTypeKind((BuiltinType::Kind) K));
5058  if (const BuiltinType *BT = dyn_cast<BuiltinType>(this))
5059    return (BT->getKind() == (BuiltinType::Kind) K);
5060  return false;
5061}
5062
5063inline bool Type::isNonOverloadPlaceholderType() const {
5064  if (const BuiltinType *BT = dyn_cast<BuiltinType>(this))
5065    return BT->isNonOverloadPlaceholderType();
5066  return false;
5067}
5068
5069inline bool Type::isVoidType() const {
5070  if (const BuiltinType *BT = dyn_cast<BuiltinType>(CanonicalType))
5071    return BT->getKind() == BuiltinType::Void;
5072  return false;
5073}
5074
5075inline bool Type::isHalfType() const {
5076  if (const BuiltinType *BT = dyn_cast<BuiltinType>(CanonicalType))
5077    return BT->getKind() == BuiltinType::Half;
5078  // FIXME: Should we allow complex __fp16? Probably not.
5079  return false;
5080}
5081
5082inline bool Type::isNullPtrType() const {
5083  if (const BuiltinType *BT = getAs<BuiltinType>())
5084    return BT->getKind() == BuiltinType::NullPtr;
5085  return false;
5086}
5087
5088extern bool IsEnumDeclComplete(EnumDecl *);
5089extern bool IsEnumDeclScoped(EnumDecl *);
5090
5091inline bool Type::isIntegerType() const {
5092  if (const BuiltinType *BT = dyn_cast<BuiltinType>(CanonicalType))
5093    return BT->getKind() >= BuiltinType::Bool &&
5094           BT->getKind() <= BuiltinType::Int128;
5095  if (const EnumType *ET = dyn_cast<EnumType>(CanonicalType)) {
5096    // Incomplete enum types are not treated as integer types.
5097    // FIXME: In C++, enum types are never integer types.
5098    return IsEnumDeclComplete(ET->getDecl()) &&
5099      !IsEnumDeclScoped(ET->getDecl());
5100  }
5101  return false;
5102}
5103
5104inline bool Type::isScalarType() const {
5105  if (const BuiltinType *BT = dyn_cast<BuiltinType>(CanonicalType))
5106    return BT->getKind() > BuiltinType::Void &&
5107           BT->getKind() <= BuiltinType::NullPtr;
5108  if (const EnumType *ET = dyn_cast<EnumType>(CanonicalType))
5109    // Enums are scalar types, but only if they are defined.  Incomplete enums
5110    // are not treated as scalar types.
5111    return IsEnumDeclComplete(ET->getDecl());
5112  return isa<PointerType>(CanonicalType) ||
5113         isa<BlockPointerType>(CanonicalType) ||
5114         isa<MemberPointerType>(CanonicalType) ||
5115         isa<ComplexType>(CanonicalType) ||
5116         isa<ObjCObjectPointerType>(CanonicalType);
5117}
5118
5119inline bool Type::isIntegralOrEnumerationType() const {
5120  if (const BuiltinType *BT = dyn_cast<BuiltinType>(CanonicalType))
5121    return BT->getKind() >= BuiltinType::Bool &&
5122           BT->getKind() <= BuiltinType::Int128;
5123
5124  // Check for a complete enum type; incomplete enum types are not properly an
5125  // enumeration type in the sense required here.
5126  if (const EnumType *ET = dyn_cast<EnumType>(CanonicalType))
5127    return IsEnumDeclComplete(ET->getDecl());
5128
5129  return false;
5130}
5131
5132inline bool Type::isBooleanType() const {
5133  if (const BuiltinType *BT = dyn_cast<BuiltinType>(CanonicalType))
5134    return BT->getKind() == BuiltinType::Bool;
5135  return false;
5136}
5137
5138inline bool Type::isUndeducedType() const {
5139  const AutoType *AT = getContainedAutoType();
5140  return AT && !AT->isDeduced();
5141}
5142
5143/// \brief Determines whether this is a type for which one can define
5144/// an overloaded operator.
5145inline bool Type::isOverloadableType() const {
5146  return isDependentType() || isRecordType() || isEnumeralType();
5147}
5148
5149/// \brief Determines whether this type can decay to a pointer type.
5150inline bool Type::canDecayToPointerType() const {
5151  return isFunctionType() || isArrayType();
5152}
5153
5154inline bool Type::hasPointerRepresentation() const {
5155  return (isPointerType() || isReferenceType() || isBlockPointerType() ||
5156          isObjCObjectPointerType() || isNullPtrType());
5157}
5158
5159inline bool Type::hasObjCPointerRepresentation() const {
5160  return isObjCObjectPointerType();
5161}
5162
5163inline const Type *Type::getBaseElementTypeUnsafe() const {
5164  const Type *type = this;
5165  while (const ArrayType *arrayType = type->getAsArrayTypeUnsafe())
5166    type = arrayType->getElementType().getTypePtr();
5167  return type;
5168}
5169
5170/// Insertion operator for diagnostics.  This allows sending QualType's into a
5171/// diagnostic with <<.
5172inline const DiagnosticBuilder &operator<<(const DiagnosticBuilder &DB,
5173                                           QualType T) {
5174  DB.AddTaggedVal(reinterpret_cast<intptr_t>(T.getAsOpaquePtr()),
5175                  DiagnosticsEngine::ak_qualtype);
5176  return DB;
5177}
5178
5179/// Insertion operator for partial diagnostics.  This allows sending QualType's
5180/// into a diagnostic with <<.
5181inline const PartialDiagnostic &operator<<(const PartialDiagnostic &PD,
5182                                           QualType T) {
5183  PD.AddTaggedVal(reinterpret_cast<intptr_t>(T.getAsOpaquePtr()),
5184                  DiagnosticsEngine::ak_qualtype);
5185  return PD;
5186}
5187
5188// Helper class template that is used by Type::getAs to ensure that one does
5189// not try to look through a qualified type to get to an array type.
5190template <typename T, bool isArrayType = (std::is_same<T, ArrayType>::value ||
5191                                          std::is_base_of<ArrayType, T>::value)>
5192struct ArrayType_cannot_be_used_with_getAs {};
5193
5194template<typename T>
5195struct ArrayType_cannot_be_used_with_getAs<T, true>;
5196
5197// Member-template getAs<specific type>'.
5198template <typename T> const T *Type::getAs() const {
5199  ArrayType_cannot_be_used_with_getAs<T> at;
5200  (void)at;
5201
5202  // If this is directly a T type, return it.
5203  if (const T *Ty = dyn_cast<T>(this))
5204    return Ty;
5205
5206  // If the canonical form of this type isn't the right kind, reject it.
5207  if (!isa<T>(CanonicalType))
5208    return 0;
5209
5210  // If this is a typedef for the type, strip the typedef off without
5211  // losing all typedef information.
5212  return cast<T>(getUnqualifiedDesugaredType());
5213}
5214
5215inline const ArrayType *Type::getAsArrayTypeUnsafe() const {
5216  // If this is directly an array type, return it.
5217  if (const ArrayType *arr = dyn_cast<ArrayType>(this))
5218    return arr;
5219
5220  // If the canonical form of this type isn't the right kind, reject it.
5221  if (!isa<ArrayType>(CanonicalType))
5222    return 0;
5223
5224  // If this is a typedef for the type, strip the typedef off without
5225  // losing all typedef information.
5226  return cast<ArrayType>(getUnqualifiedDesugaredType());
5227}
5228
5229template <typename T> const T *Type::castAs() const {
5230  ArrayType_cannot_be_used_with_getAs<T> at;
5231  (void) at;
5232
5233  assert(isa<T>(CanonicalType));
5234  if (const T *ty = dyn_cast<T>(this)) return ty;
5235  return cast<T>(getUnqualifiedDesugaredType());
5236}
5237
5238inline const ArrayType *Type::castAsArrayTypeUnsafe() const {
5239  assert(isa<ArrayType>(CanonicalType));
5240  if (const ArrayType *arr = dyn_cast<ArrayType>(this)) return arr;
5241  return cast<ArrayType>(getUnqualifiedDesugaredType());
5242}
5243
5244}  // end namespace clang
5245
5246#endif
5247