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  1. //===- DeclBase.h - Base Classes for representing declarations --*- C++ -*-===//
  2. //
  3. // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
  4. // See https://llvm.org/LICENSE.txt for license information.
  5. // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
  6. //
  7. //===----------------------------------------------------------------------===//
  8. //
  9. //  This file defines the Decl and DeclContext interfaces.
  10. //
  11. //===----------------------------------------------------------------------===//
  12.  
  13. #ifndef LLVM_CLANG_AST_DECLBASE_H
  14. #define LLVM_CLANG_AST_DECLBASE_H
  15.  
  16. #include "clang/AST/ASTDumperUtils.h"
  17. #include "clang/AST/AttrIterator.h"
  18. #include "clang/AST/DeclarationName.h"
  19. #include "clang/Basic/IdentifierTable.h"
  20. #include "clang/Basic/LLVM.h"
  21. #include "clang/Basic/SourceLocation.h"
  22. #include "clang/Basic/Specifiers.h"
  23. #include "llvm/ADT/ArrayRef.h"
  24. #include "llvm/ADT/PointerIntPair.h"
  25. #include "llvm/ADT/PointerUnion.h"
  26. #include "llvm/ADT/iterator.h"
  27. #include "llvm/ADT/iterator_range.h"
  28. #include "llvm/Support/Casting.h"
  29. #include "llvm/Support/Compiler.h"
  30. #include "llvm/Support/PrettyStackTrace.h"
  31. #include "llvm/Support/VersionTuple.h"
  32. #include <algorithm>
  33. #include <cassert>
  34. #include <cstddef>
  35. #include <iterator>
  36. #include <string>
  37. #include <type_traits>
  38. #include <utility>
  39.  
  40. namespace clang {
  41.  
  42. class ASTContext;
  43. class ASTMutationListener;
  44. class Attr;
  45. class BlockDecl;
  46. class DeclContext;
  47. class ExternalSourceSymbolAttr;
  48. class FunctionDecl;
  49. class FunctionType;
  50. class IdentifierInfo;
  51. enum Linkage : unsigned char;
  52. class LinkageSpecDecl;
  53. class Module;
  54. class NamedDecl;
  55. class ObjCContainerDecl;
  56. class ObjCMethodDecl;
  57. struct PrintingPolicy;
  58. class RecordDecl;
  59. class SourceManager;
  60. class Stmt;
  61. class StoredDeclsMap;
  62. class TemplateDecl;
  63. class TemplateParameterList;
  64. class TranslationUnitDecl;
  65. class UsingDirectiveDecl;
  66.  
  67. /// Captures the result of checking the availability of a
  68. /// declaration.
  69. enum AvailabilityResult {
  70.   AR_Available = 0,
  71.   AR_NotYetIntroduced,
  72.   AR_Deprecated,
  73.   AR_Unavailable
  74. };
  75.  
  76. /// Decl - This represents one declaration (or definition), e.g. a variable,
  77. /// typedef, function, struct, etc.
  78. ///
  79. /// Note: There are objects tacked on before the *beginning* of Decl
  80. /// (and its subclasses) in its Decl::operator new(). Proper alignment
  81. /// of all subclasses (not requiring more than the alignment of Decl) is
  82. /// asserted in DeclBase.cpp.
  83. class alignas(8) Decl {
  84. public:
  85.   /// Lists the kind of concrete classes of Decl.
  86.   enum Kind {
  87. #define DECL(DERIVED, BASE) DERIVED,
  88. #define ABSTRACT_DECL(DECL)
  89. #define DECL_RANGE(BASE, START, END) \
  90.         first##BASE = START, last##BASE = END,
  91. #define LAST_DECL_RANGE(BASE, START, END) \
  92.         first##BASE = START, last##BASE = END
  93. #include "clang/AST/DeclNodes.inc"
  94.   };
  95.  
  96.   /// A placeholder type used to construct an empty shell of a
  97.   /// decl-derived type that will be filled in later (e.g., by some
  98.   /// deserialization method).
  99.   struct EmptyShell {};
  100.  
  101.   /// IdentifierNamespace - The different namespaces in which
  102.   /// declarations may appear.  According to C99 6.2.3, there are
  103.   /// four namespaces, labels, tags, members and ordinary
  104.   /// identifiers.  C++ describes lookup completely differently:
  105.   /// certain lookups merely "ignore" certain kinds of declarations,
  106.   /// usually based on whether the declaration is of a type, etc.
  107.   ///
  108.   /// These are meant as bitmasks, so that searches in
  109.   /// C++ can look into the "tag" namespace during ordinary lookup.
  110.   ///
  111.   /// Decl currently provides 15 bits of IDNS bits.
  112.   enum IdentifierNamespace {
  113.     /// Labels, declared with 'x:' and referenced with 'goto x'.
  114.     IDNS_Label               = 0x0001,
  115.  
  116.     /// Tags, declared with 'struct foo;' and referenced with
  117.     /// 'struct foo'.  All tags are also types.  This is what
  118.     /// elaborated-type-specifiers look for in C.
  119.     /// This also contains names that conflict with tags in the
  120.     /// same scope but that are otherwise ordinary names (non-type
  121.     /// template parameters and indirect field declarations).
  122.     IDNS_Tag                 = 0x0002,
  123.  
  124.     /// Types, declared with 'struct foo', typedefs, etc.
  125.     /// This is what elaborated-type-specifiers look for in C++,
  126.     /// but note that it's ill-formed to find a non-tag.
  127.     IDNS_Type                = 0x0004,
  128.  
  129.     /// Members, declared with object declarations within tag
  130.     /// definitions.  In C, these can only be found by "qualified"
  131.     /// lookup in member expressions.  In C++, they're found by
  132.     /// normal lookup.
  133.     IDNS_Member              = 0x0008,
  134.  
  135.     /// Namespaces, declared with 'namespace foo {}'.
  136.     /// Lookup for nested-name-specifiers find these.
  137.     IDNS_Namespace           = 0x0010,
  138.  
  139.     /// Ordinary names.  In C, everything that's not a label, tag,
  140.     /// member, or function-local extern ends up here.
  141.     IDNS_Ordinary            = 0x0020,
  142.  
  143.     /// Objective C \@protocol.
  144.     IDNS_ObjCProtocol        = 0x0040,
  145.  
  146.     /// This declaration is a friend function.  A friend function
  147.     /// declaration is always in this namespace but may also be in
  148.     /// IDNS_Ordinary if it was previously declared.
  149.     IDNS_OrdinaryFriend      = 0x0080,
  150.  
  151.     /// This declaration is a friend class.  A friend class
  152.     /// declaration is always in this namespace but may also be in
  153.     /// IDNS_Tag|IDNS_Type if it was previously declared.
  154.     IDNS_TagFriend           = 0x0100,
  155.  
  156.     /// This declaration is a using declaration.  A using declaration
  157.     /// *introduces* a number of other declarations into the current
  158.     /// scope, and those declarations use the IDNS of their targets,
  159.     /// but the actual using declarations go in this namespace.
  160.     IDNS_Using               = 0x0200,
  161.  
  162.     /// This declaration is a C++ operator declared in a non-class
  163.     /// context.  All such operators are also in IDNS_Ordinary.
  164.     /// C++ lexical operator lookup looks for these.
  165.     IDNS_NonMemberOperator   = 0x0400,
  166.  
  167.     /// This declaration is a function-local extern declaration of a
  168.     /// variable or function. This may also be IDNS_Ordinary if it
  169.     /// has been declared outside any function. These act mostly like
  170.     /// invisible friend declarations, but are also visible to unqualified
  171.     /// lookup within the scope of the declaring function.
  172.     IDNS_LocalExtern         = 0x0800,
  173.  
  174.     /// This declaration is an OpenMP user defined reduction construction.
  175.     IDNS_OMPReduction        = 0x1000,
  176.  
  177.     /// This declaration is an OpenMP user defined mapper.
  178.     IDNS_OMPMapper           = 0x2000,
  179.   };
  180.  
  181.   /// ObjCDeclQualifier - 'Qualifiers' written next to the return and
  182.   /// parameter types in method declarations.  Other than remembering
  183.   /// them and mangling them into the method's signature string, these
  184.   /// are ignored by the compiler; they are consumed by certain
  185.   /// remote-messaging frameworks.
  186.   ///
  187.   /// in, inout, and out are mutually exclusive and apply only to
  188.   /// method parameters.  bycopy and byref are mutually exclusive and
  189.   /// apply only to method parameters (?).  oneway applies only to
  190.   /// results.  All of these expect their corresponding parameter to
  191.   /// have a particular type.  None of this is currently enforced by
  192.   /// clang.
  193.   ///
  194.   /// This should be kept in sync with ObjCDeclSpec::ObjCDeclQualifier.
  195.   enum ObjCDeclQualifier {
  196.     OBJC_TQ_None = 0x0,
  197.     OBJC_TQ_In = 0x1,
  198.     OBJC_TQ_Inout = 0x2,
  199.     OBJC_TQ_Out = 0x4,
  200.     OBJC_TQ_Bycopy = 0x8,
  201.     OBJC_TQ_Byref = 0x10,
  202.     OBJC_TQ_Oneway = 0x20,
  203.  
  204.     /// The nullability qualifier is set when the nullability of the
  205.     /// result or parameter was expressed via a context-sensitive
  206.     /// keyword.
  207.     OBJC_TQ_CSNullability = 0x40
  208.   };
  209.  
  210.   /// The kind of ownership a declaration has, for visibility purposes.
  211.   /// This enumeration is designed such that higher values represent higher
  212.   /// levels of name hiding.
  213.   enum class ModuleOwnershipKind : unsigned {
  214.     /// This declaration is not owned by a module.
  215.     Unowned,
  216.  
  217.     /// This declaration has an owning module, but is globally visible
  218.     /// (typically because its owning module is visible and we know that
  219.     /// modules cannot later become hidden in this compilation).
  220.     /// After serialization and deserialization, this will be converted
  221.     /// to VisibleWhenImported.
  222.     Visible,
  223.  
  224.     /// This declaration has an owning module, and is visible when that
  225.     /// module is imported.
  226.     VisibleWhenImported,
  227.  
  228.     /// This declaration has an owning module, and is visible to lookups
  229.     /// that occurs within that module. And it is reachable in other module
  230.     /// when the owning module is transitively imported.
  231.     ReachableWhenImported,
  232.  
  233.     /// This declaration has an owning module, but is only visible to
  234.     /// lookups that occur within that module.
  235.     /// The discarded declarations in global module fragment belongs
  236.     /// to this group too.
  237.     ModulePrivate
  238.   };
  239.  
  240. protected:
  241.   /// The next declaration within the same lexical
  242.   /// DeclContext. These pointers form the linked list that is
  243.   /// traversed via DeclContext's decls_begin()/decls_end().
  244.   ///
  245.   /// The extra three bits are used for the ModuleOwnershipKind.
  246.   llvm::PointerIntPair<Decl *, 3, ModuleOwnershipKind> NextInContextAndBits;
  247.  
  248. private:
  249.   friend class DeclContext;
  250.  
  251.   struct MultipleDC {
  252.     DeclContext *SemanticDC;
  253.     DeclContext *LexicalDC;
  254.   };
  255.  
  256.   /// DeclCtx - Holds either a DeclContext* or a MultipleDC*.
  257.   /// For declarations that don't contain C++ scope specifiers, it contains
  258.   /// the DeclContext where the Decl was declared.
  259.   /// For declarations with C++ scope specifiers, it contains a MultipleDC*
  260.   /// with the context where it semantically belongs (SemanticDC) and the
  261.   /// context where it was lexically declared (LexicalDC).
  262.   /// e.g.:
  263.   ///
  264.   ///   namespace A {
  265.   ///      void f(); // SemanticDC == LexicalDC == 'namespace A'
  266.   ///   }
  267.   ///   void A::f(); // SemanticDC == namespace 'A'
  268.   ///                // LexicalDC == global namespace
  269.   llvm::PointerUnion<DeclContext*, MultipleDC*> DeclCtx;
  270.  
  271.   bool isInSemaDC() const { return DeclCtx.is<DeclContext*>(); }
  272.   bool isOutOfSemaDC() const { return DeclCtx.is<MultipleDC*>(); }
  273.  
  274.   MultipleDC *getMultipleDC() const {
  275.     return DeclCtx.get<MultipleDC*>();
  276.   }
  277.  
  278.   DeclContext *getSemanticDC() const {
  279.     return DeclCtx.get<DeclContext*>();
  280.   }
  281.  
  282.   /// Loc - The location of this decl.
  283.   SourceLocation Loc;
  284.  
  285.   /// DeclKind - This indicates which class this is.
  286.   unsigned DeclKind : 7;
  287.  
  288.   /// InvalidDecl - This indicates a semantic error occurred.
  289.   unsigned InvalidDecl :  1;
  290.  
  291.   /// HasAttrs - This indicates whether the decl has attributes or not.
  292.   unsigned HasAttrs : 1;
  293.  
  294.   /// Implicit - Whether this declaration was implicitly generated by
  295.   /// the implementation rather than explicitly written by the user.
  296.   unsigned Implicit : 1;
  297.  
  298.   /// Whether this declaration was "used", meaning that a definition is
  299.   /// required.
  300.   unsigned Used : 1;
  301.  
  302.   /// Whether this declaration was "referenced".
  303.   /// The difference with 'Used' is whether the reference appears in a
  304.   /// evaluated context or not, e.g. functions used in uninstantiated templates
  305.   /// are regarded as "referenced" but not "used".
  306.   unsigned Referenced : 1;
  307.  
  308.   /// Whether this declaration is a top-level declaration (function,
  309.   /// global variable, etc.) that is lexically inside an objc container
  310.   /// definition.
  311.   unsigned TopLevelDeclInObjCContainer : 1;
  312.  
  313.   /// Whether statistic collection is enabled.
  314.   static bool StatisticsEnabled;
  315.  
  316. protected:
  317.   friend class ASTDeclReader;
  318.   friend class ASTDeclWriter;
  319.   friend class ASTNodeImporter;
  320.   friend class ASTReader;
  321.   friend class CXXClassMemberWrapper;
  322.   friend class LinkageComputer;
  323.   friend class RecordDecl;
  324.   template<typename decl_type> friend class Redeclarable;
  325.  
  326.   /// Access - Used by C++ decls for the access specifier.
  327.   // NOTE: VC++ treats enums as signed, avoid using the AccessSpecifier enum
  328.   unsigned Access : 2;
  329.  
  330.   /// Whether this declaration was loaded from an AST file.
  331.   unsigned FromASTFile : 1;
  332.  
  333.   /// IdentifierNamespace - This specifies what IDNS_* namespace this lives in.
  334.   unsigned IdentifierNamespace : 14;
  335.  
  336.   /// If 0, we have not computed the linkage of this declaration.
  337.   /// Otherwise, it is the linkage + 1.
  338.   mutable unsigned CacheValidAndLinkage : 3;
  339.  
  340.   /// Allocate memory for a deserialized declaration.
  341.   ///
  342.   /// This routine must be used to allocate memory for any declaration that is
  343.   /// deserialized from a module file.
  344.   ///
  345.   /// \param Size The size of the allocated object.
  346.   /// \param Ctx The context in which we will allocate memory.
  347.   /// \param ID The global ID of the deserialized declaration.
  348.   /// \param Extra The amount of extra space to allocate after the object.
  349.   void *operator new(std::size_t Size, const ASTContext &Ctx, unsigned ID,
  350.                      std::size_t Extra = 0);
  351.  
  352.   /// Allocate memory for a non-deserialized declaration.
  353.   void *operator new(std::size_t Size, const ASTContext &Ctx,
  354.                      DeclContext *Parent, std::size_t Extra = 0);
  355.  
  356. private:
  357.   bool AccessDeclContextCheck() const;
  358.  
  359.   /// Get the module ownership kind to use for a local lexical child of \p DC,
  360.   /// which may be either a local or (rarely) an imported declaration.
  361.   static ModuleOwnershipKind getModuleOwnershipKindForChildOf(DeclContext *DC) {
  362.     if (DC) {
  363.       auto *D = cast<Decl>(DC);
  364.       auto MOK = D->getModuleOwnershipKind();
  365.       if (MOK != ModuleOwnershipKind::Unowned &&
  366.           (!D->isFromASTFile() || D->hasLocalOwningModuleStorage()))
  367.         return MOK;
  368.       // If D is not local and we have no local module storage, then we don't
  369.       // need to track module ownership at all.
  370.     }
  371.     return ModuleOwnershipKind::Unowned;
  372.   }
  373.  
  374. public:
  375.   Decl() = delete;
  376.   Decl(const Decl&) = delete;
  377.   Decl(Decl &&) = delete;
  378.   Decl &operator=(const Decl&) = delete;
  379.   Decl &operator=(Decl&&) = delete;
  380.  
  381. protected:
  382.   Decl(Kind DK, DeclContext *DC, SourceLocation L)
  383.       : NextInContextAndBits(nullptr, getModuleOwnershipKindForChildOf(DC)),
  384.         DeclCtx(DC), Loc(L), DeclKind(DK), InvalidDecl(false), HasAttrs(false),
  385.         Implicit(false), Used(false), Referenced(false),
  386.         TopLevelDeclInObjCContainer(false), Access(AS_none), FromASTFile(0),
  387.         IdentifierNamespace(getIdentifierNamespaceForKind(DK)),
  388.         CacheValidAndLinkage(0) {
  389.     if (StatisticsEnabled) add(DK);
  390.   }
  391.  
  392.   Decl(Kind DK, EmptyShell Empty)
  393.       : DeclKind(DK), InvalidDecl(false), HasAttrs(false), Implicit(false),
  394.         Used(false), Referenced(false), TopLevelDeclInObjCContainer(false),
  395.         Access(AS_none), FromASTFile(0),
  396.         IdentifierNamespace(getIdentifierNamespaceForKind(DK)),
  397.         CacheValidAndLinkage(0) {
  398.     if (StatisticsEnabled) add(DK);
  399.   }
  400.  
  401.   virtual ~Decl();
  402.  
  403.   /// Update a potentially out-of-date declaration.
  404.   void updateOutOfDate(IdentifierInfo &II) const;
  405.  
  406.   Linkage getCachedLinkage() const {
  407.     return Linkage(CacheValidAndLinkage - 1);
  408.   }
  409.  
  410.   void setCachedLinkage(Linkage L) const {
  411.     CacheValidAndLinkage = L + 1;
  412.   }
  413.  
  414.   bool hasCachedLinkage() const {
  415.     return CacheValidAndLinkage;
  416.   }
  417.  
  418. public:
  419.   /// Source range that this declaration covers.
  420.   virtual SourceRange getSourceRange() const LLVM_READONLY {
  421.     return SourceRange(getLocation(), getLocation());
  422.   }
  423.  
  424.   SourceLocation getBeginLoc() const LLVM_READONLY {
  425.     return getSourceRange().getBegin();
  426.   }
  427.  
  428.   SourceLocation getEndLoc() const LLVM_READONLY {
  429.     return getSourceRange().getEnd();
  430.   }
  431.  
  432.   SourceLocation getLocation() const { return Loc; }
  433.   void setLocation(SourceLocation L) { Loc = L; }
  434.  
  435.   Kind getKind() const { return static_cast<Kind>(DeclKind); }
  436.   const char *getDeclKindName() const;
  437.  
  438.   Decl *getNextDeclInContext() { return NextInContextAndBits.getPointer(); }
  439.   const Decl *getNextDeclInContext() const {return NextInContextAndBits.getPointer();}
  440.  
  441.   DeclContext *getDeclContext() {
  442.     if (isInSemaDC())
  443.       return getSemanticDC();
  444.     return getMultipleDC()->SemanticDC;
  445.   }
  446.   const DeclContext *getDeclContext() const {
  447.     return const_cast<Decl*>(this)->getDeclContext();
  448.   }
  449.  
  450.   /// Return the non transparent context.
  451.   /// See the comment of `DeclContext::isTransparentContext()` for the
  452.   /// definition of transparent context.
  453.   DeclContext *getNonTransparentDeclContext();
  454.   const DeclContext *getNonTransparentDeclContext() const {
  455.     return const_cast<Decl *>(this)->getNonTransparentDeclContext();
  456.   }
  457.  
  458.   /// Find the innermost non-closure ancestor of this declaration,
  459.   /// walking up through blocks, lambdas, etc.  If that ancestor is
  460.   /// not a code context (!isFunctionOrMethod()), returns null.
  461.   ///
  462.   /// A declaration may be its own non-closure context.
  463.   Decl *getNonClosureContext();
  464.   const Decl *getNonClosureContext() const {
  465.     return const_cast<Decl*>(this)->getNonClosureContext();
  466.   }
  467.  
  468.   TranslationUnitDecl *getTranslationUnitDecl();
  469.   const TranslationUnitDecl *getTranslationUnitDecl() const {
  470.     return const_cast<Decl*>(this)->getTranslationUnitDecl();
  471.   }
  472.  
  473.   bool isInAnonymousNamespace() const;
  474.  
  475.   bool isInStdNamespace() const;
  476.  
  477.   // Return true if this is a FileContext Decl.
  478.   bool isFileContextDecl() const;
  479.  
  480.   ASTContext &getASTContext() const LLVM_READONLY;
  481.  
  482.   /// Helper to get the language options from the ASTContext.
  483.   /// Defined out of line to avoid depending on ASTContext.h.
  484.   const LangOptions &getLangOpts() const LLVM_READONLY;
  485.  
  486.   void setAccess(AccessSpecifier AS) {
  487.     Access = AS;
  488.     assert(AccessDeclContextCheck());
  489.   }
  490.  
  491.   AccessSpecifier getAccess() const {
  492.     assert(AccessDeclContextCheck());
  493.     return AccessSpecifier(Access);
  494.   }
  495.  
  496.   /// Retrieve the access specifier for this declaration, even though
  497.   /// it may not yet have been properly set.
  498.   AccessSpecifier getAccessUnsafe() const {
  499.     return AccessSpecifier(Access);
  500.   }
  501.  
  502.   bool hasAttrs() const { return HasAttrs; }
  503.  
  504.   void setAttrs(const AttrVec& Attrs) {
  505.     return setAttrsImpl(Attrs, getASTContext());
  506.   }
  507.  
  508.   AttrVec &getAttrs() {
  509.     return const_cast<AttrVec&>(const_cast<const Decl*>(this)->getAttrs());
  510.   }
  511.  
  512.   const AttrVec &getAttrs() const;
  513.   void dropAttrs();
  514.   void addAttr(Attr *A);
  515.  
  516.   using attr_iterator = AttrVec::const_iterator;
  517.   using attr_range = llvm::iterator_range<attr_iterator>;
  518.  
  519.   attr_range attrs() const {
  520.     return attr_range(attr_begin(), attr_end());
  521.   }
  522.  
  523.   attr_iterator attr_begin() const {
  524.     return hasAttrs() ? getAttrs().begin() : nullptr;
  525.   }
  526.   attr_iterator attr_end() const {
  527.     return hasAttrs() ? getAttrs().end() : nullptr;
  528.   }
  529.  
  530.   template <typename T>
  531.   void dropAttr() {
  532.     if (!HasAttrs) return;
  533.  
  534.     AttrVec &Vec = getAttrs();
  535.     llvm::erase_if(Vec, [](Attr *A) { return isa<T>(A); });
  536.  
  537.     if (Vec.empty())
  538.       HasAttrs = false;
  539.   }
  540.  
  541.   template <typename T>
  542.   llvm::iterator_range<specific_attr_iterator<T>> specific_attrs() const {
  543.     return llvm::make_range(specific_attr_begin<T>(), specific_attr_end<T>());
  544.   }
  545.  
  546.   template <typename T>
  547.   specific_attr_iterator<T> specific_attr_begin() const {
  548.     return specific_attr_iterator<T>(attr_begin());
  549.   }
  550.  
  551.   template <typename T>
  552.   specific_attr_iterator<T> specific_attr_end() const {
  553.     return specific_attr_iterator<T>(attr_end());
  554.   }
  555.  
  556.   template<typename T> T *getAttr() const {
  557.     return hasAttrs() ? getSpecificAttr<T>(getAttrs()) : nullptr;
  558.   }
  559.  
  560.   template<typename T> bool hasAttr() const {
  561.     return hasAttrs() && hasSpecificAttr<T>(getAttrs());
  562.   }
  563.  
  564.   /// getMaxAlignment - return the maximum alignment specified by attributes
  565.   /// on this decl, 0 if there are none.
  566.   unsigned getMaxAlignment() const;
  567.  
  568.   /// setInvalidDecl - Indicates the Decl had a semantic error. This
  569.   /// allows for graceful error recovery.
  570.   void setInvalidDecl(bool Invalid = true);
  571.   bool isInvalidDecl() const { return (bool) InvalidDecl; }
  572.  
  573.   /// isImplicit - Indicates whether the declaration was implicitly
  574.   /// generated by the implementation. If false, this declaration
  575.   /// was written explicitly in the source code.
  576.   bool isImplicit() const { return Implicit; }
  577.   void setImplicit(bool I = true) { Implicit = I; }
  578.  
  579.   /// Whether *any* (re-)declaration of the entity was used, meaning that
  580.   /// a definition is required.
  581.   ///
  582.   /// \param CheckUsedAttr When true, also consider the "used" attribute
  583.   /// (in addition to the "used" bit set by \c setUsed()) when determining
  584.   /// whether the function is used.
  585.   bool isUsed(bool CheckUsedAttr = true) const;
  586.  
  587.   /// Set whether the declaration is used, in the sense of odr-use.
  588.   ///
  589.   /// This should only be used immediately after creating a declaration.
  590.   /// It intentionally doesn't notify any listeners.
  591.   void setIsUsed() { getCanonicalDecl()->Used = true; }
  592.  
  593.   /// Mark the declaration used, in the sense of odr-use.
  594.   ///
  595.   /// This notifies any mutation listeners in addition to setting a bit
  596.   /// indicating the declaration is used.
  597.   void markUsed(ASTContext &C);
  598.  
  599.   /// Whether any declaration of this entity was referenced.
  600.   bool isReferenced() const;
  601.  
  602.   /// Whether this declaration was referenced. This should not be relied
  603.   /// upon for anything other than debugging.
  604.   bool isThisDeclarationReferenced() const { return Referenced; }
  605.  
  606.   void setReferenced(bool R = true) { Referenced = R; }
  607.  
  608.   /// Whether this declaration is a top-level declaration (function,
  609.   /// global variable, etc.) that is lexically inside an objc container
  610.   /// definition.
  611.   bool isTopLevelDeclInObjCContainer() const {
  612.     return TopLevelDeclInObjCContainer;
  613.   }
  614.  
  615.   void setTopLevelDeclInObjCContainer(bool V = true) {
  616.     TopLevelDeclInObjCContainer = V;
  617.   }
  618.  
  619.   /// Looks on this and related declarations for an applicable
  620.   /// external source symbol attribute.
  621.   ExternalSourceSymbolAttr *getExternalSourceSymbolAttr() const;
  622.  
  623.   /// Whether this declaration was marked as being private to the
  624.   /// module in which it was defined.
  625.   bool isModulePrivate() const {
  626.     return getModuleOwnershipKind() == ModuleOwnershipKind::ModulePrivate;
  627.   }
  628.  
  629.   /// Whether this declaration was exported in a lexical context.
  630.   /// e.g.:
  631.   ///
  632.   ///   export namespace A {
  633.   ///      void f1();        // isInExportDeclContext() == true
  634.   ///   }
  635.   ///   void A::f1();        // isInExportDeclContext() == false
  636.   ///
  637.   ///   namespace B {
  638.   ///      void f2();        // isInExportDeclContext() == false
  639.   ///   }
  640.   ///   export void B::f2(); // isInExportDeclContext() == true
  641.   bool isInExportDeclContext() const;
  642.  
  643.   bool isInvisibleOutsideTheOwningModule() const {
  644.     return getModuleOwnershipKind() > ModuleOwnershipKind::VisibleWhenImported;
  645.   }
  646.  
  647.   /// FIXME: Implement discarding declarations actually in global module
  648.   /// fragment. See [module.global.frag]p3,4 for details.
  649.   bool isDiscardedInGlobalModuleFragment() const { return false; }
  650.  
  651.   /// Return true if this declaration has an attribute which acts as
  652.   /// definition of the entity, such as 'alias' or 'ifunc'.
  653.   bool hasDefiningAttr() const;
  654.  
  655.   /// Return this declaration's defining attribute if it has one.
  656.   const Attr *getDefiningAttr() const;
  657.  
  658. protected:
  659.   /// Specify that this declaration was marked as being private
  660.   /// to the module in which it was defined.
  661.   void setModulePrivate() {
  662.     // The module-private specifier has no effect on unowned declarations.
  663.     // FIXME: We should track this in some way for source fidelity.
  664.     if (getModuleOwnershipKind() == ModuleOwnershipKind::Unowned)
  665.       return;
  666.     setModuleOwnershipKind(ModuleOwnershipKind::ModulePrivate);
  667.   }
  668.  
  669. public:
  670.   /// Set the FromASTFile flag. This indicates that this declaration
  671.   /// was deserialized and not parsed from source code and enables
  672.   /// features such as module ownership information.
  673.   void setFromASTFile() {
  674.     FromASTFile = true;
  675.   }
  676.  
  677.   /// Set the owning module ID.  This may only be called for
  678.   /// deserialized Decls.
  679.   void setOwningModuleID(unsigned ID) {
  680.     assert(isFromASTFile() && "Only works on a deserialized declaration");
  681.     *((unsigned*)this - 2) = ID;
  682.   }
  683.  
  684. public:
  685.   /// Determine the availability of the given declaration.
  686.   ///
  687.   /// This routine will determine the most restrictive availability of
  688.   /// the given declaration (e.g., preferring 'unavailable' to
  689.   /// 'deprecated').
  690.   ///
  691.   /// \param Message If non-NULL and the result is not \c
  692.   /// AR_Available, will be set to a (possibly empty) message
  693.   /// describing why the declaration has not been introduced, is
  694.   /// deprecated, or is unavailable.
  695.   ///
  696.   /// \param EnclosingVersion The version to compare with. If empty, assume the
  697.   /// deployment target version.
  698.   ///
  699.   /// \param RealizedPlatform If non-NULL and the availability result is found
  700.   /// in an available attribute it will set to the platform which is written in
  701.   /// the available attribute.
  702.   AvailabilityResult
  703.   getAvailability(std::string *Message = nullptr,
  704.                   VersionTuple EnclosingVersion = VersionTuple(),
  705.                   StringRef *RealizedPlatform = nullptr) const;
  706.  
  707.   /// Retrieve the version of the target platform in which this
  708.   /// declaration was introduced.
  709.   ///
  710.   /// \returns An empty version tuple if this declaration has no 'introduced'
  711.   /// availability attributes, or the version tuple that's specified in the
  712.   /// attribute otherwise.
  713.   VersionTuple getVersionIntroduced() const;
  714.  
  715.   /// Determine whether this declaration is marked 'deprecated'.
  716.   ///
  717.   /// \param Message If non-NULL and the declaration is deprecated,
  718.   /// this will be set to the message describing why the declaration
  719.   /// was deprecated (which may be empty).
  720.   bool isDeprecated(std::string *Message = nullptr) const {
  721.     return getAvailability(Message) == AR_Deprecated;
  722.   }
  723.  
  724.   /// Determine whether this declaration is marked 'unavailable'.
  725.   ///
  726.   /// \param Message If non-NULL and the declaration is unavailable,
  727.   /// this will be set to the message describing why the declaration
  728.   /// was made unavailable (which may be empty).
  729.   bool isUnavailable(std::string *Message = nullptr) const {
  730.     return getAvailability(Message) == AR_Unavailable;
  731.   }
  732.  
  733.   /// Determine whether this is a weak-imported symbol.
  734.   ///
  735.   /// Weak-imported symbols are typically marked with the
  736.   /// 'weak_import' attribute, but may also be marked with an
  737.   /// 'availability' attribute where we're targing a platform prior to
  738.   /// the introduction of this feature.
  739.   bool isWeakImported() const;
  740.  
  741.   /// Determines whether this symbol can be weak-imported,
  742.   /// e.g., whether it would be well-formed to add the weak_import
  743.   /// attribute.
  744.   ///
  745.   /// \param IsDefinition Set to \c true to indicate that this
  746.   /// declaration cannot be weak-imported because it has a definition.
  747.   bool canBeWeakImported(bool &IsDefinition) const;
  748.  
  749.   /// Determine whether this declaration came from an AST file (such as
  750.   /// a precompiled header or module) rather than having been parsed.
  751.   bool isFromASTFile() const { return FromASTFile; }
  752.  
  753.   /// Retrieve the global declaration ID associated with this
  754.   /// declaration, which specifies where this Decl was loaded from.
  755.   unsigned getGlobalID() const {
  756.     if (isFromASTFile())
  757.       return *((const unsigned*)this - 1);
  758.     return 0;
  759.   }
  760.  
  761.   /// Retrieve the global ID of the module that owns this particular
  762.   /// declaration.
  763.   unsigned getOwningModuleID() const {
  764.     if (isFromASTFile())
  765.       return *((const unsigned*)this - 2);
  766.     return 0;
  767.   }
  768.  
  769. private:
  770.   Module *getOwningModuleSlow() const;
  771.  
  772. protected:
  773.   bool hasLocalOwningModuleStorage() const;
  774.  
  775. public:
  776.   /// Get the imported owning module, if this decl is from an imported
  777.   /// (non-local) module.
  778.   Module *getImportedOwningModule() const {
  779.     if (!isFromASTFile() || !hasOwningModule())
  780.       return nullptr;
  781.  
  782.     return getOwningModuleSlow();
  783.   }
  784.  
  785.   /// Get the local owning module, if known. Returns nullptr if owner is
  786.   /// not yet known or declaration is not from a module.
  787.   Module *getLocalOwningModule() const {
  788.     if (isFromASTFile() || !hasOwningModule())
  789.       return nullptr;
  790.  
  791.     assert(hasLocalOwningModuleStorage() &&
  792.            "owned local decl but no local module storage");
  793.     return reinterpret_cast<Module *const *>(this)[-1];
  794.   }
  795.   void setLocalOwningModule(Module *M) {
  796.     assert(!isFromASTFile() && hasOwningModule() &&
  797.            hasLocalOwningModuleStorage() &&
  798.            "should not have a cached owning module");
  799.     reinterpret_cast<Module **>(this)[-1] = M;
  800.   }
  801.  
  802.   /// Is this declaration owned by some module?
  803.   bool hasOwningModule() const {
  804.     return getModuleOwnershipKind() != ModuleOwnershipKind::Unowned;
  805.   }
  806.  
  807.   /// Get the module that owns this declaration (for visibility purposes).
  808.   Module *getOwningModule() const {
  809.     return isFromASTFile() ? getImportedOwningModule() : getLocalOwningModule();
  810.   }
  811.  
  812.   /// Get the module that owns this declaration for linkage purposes.
  813.   /// There only ever is such a module under the C++ Modules TS.
  814.   ///
  815.   /// \param IgnoreLinkage Ignore the linkage of the entity; assume that
  816.   /// all declarations in a global module fragment are unowned.
  817.   Module *getOwningModuleForLinkage(bool IgnoreLinkage = false) const;
  818.  
  819.   /// Determine whether this declaration is definitely visible to name lookup,
  820.   /// independent of whether the owning module is visible.
  821.   /// Note: The declaration may be visible even if this returns \c false if the
  822.   /// owning module is visible within the query context. This is a low-level
  823.   /// helper function; most code should be calling Sema::isVisible() instead.
  824.   bool isUnconditionallyVisible() const {
  825.     return (int)getModuleOwnershipKind() <= (int)ModuleOwnershipKind::Visible;
  826.   }
  827.  
  828.   bool isReachable() const {
  829.     return (int)getModuleOwnershipKind() <=
  830.            (int)ModuleOwnershipKind::ReachableWhenImported;
  831.   }
  832.  
  833.   /// Set that this declaration is globally visible, even if it came from a
  834.   /// module that is not visible.
  835.   void setVisibleDespiteOwningModule() {
  836.     if (!isUnconditionallyVisible())
  837.       setModuleOwnershipKind(ModuleOwnershipKind::Visible);
  838.   }
  839.  
  840.   /// Get the kind of module ownership for this declaration.
  841.   ModuleOwnershipKind getModuleOwnershipKind() const {
  842.     return NextInContextAndBits.getInt();
  843.   }
  844.  
  845.   /// Set whether this declaration is hidden from name lookup.
  846.   void setModuleOwnershipKind(ModuleOwnershipKind MOK) {
  847.     assert(!(getModuleOwnershipKind() == ModuleOwnershipKind::Unowned &&
  848.              MOK != ModuleOwnershipKind::Unowned && !isFromASTFile() &&
  849.              !hasLocalOwningModuleStorage()) &&
  850.            "no storage available for owning module for this declaration");
  851.     NextInContextAndBits.setInt(MOK);
  852.   }
  853.  
  854.   unsigned getIdentifierNamespace() const {
  855.     return IdentifierNamespace;
  856.   }
  857.  
  858.   bool isInIdentifierNamespace(unsigned NS) const {
  859.     return getIdentifierNamespace() & NS;
  860.   }
  861.  
  862.   static unsigned getIdentifierNamespaceForKind(Kind DK);
  863.  
  864.   bool hasTagIdentifierNamespace() const {
  865.     return isTagIdentifierNamespace(getIdentifierNamespace());
  866.   }
  867.  
  868.   static bool isTagIdentifierNamespace(unsigned NS) {
  869.     // TagDecls have Tag and Type set and may also have TagFriend.
  870.     return (NS & ~IDNS_TagFriend) == (IDNS_Tag | IDNS_Type);
  871.   }
  872.  
  873.   /// getLexicalDeclContext - The declaration context where this Decl was
  874.   /// lexically declared (LexicalDC). May be different from
  875.   /// getDeclContext() (SemanticDC).
  876.   /// e.g.:
  877.   ///
  878.   ///   namespace A {
  879.   ///      void f(); // SemanticDC == LexicalDC == 'namespace A'
  880.   ///   }
  881.   ///   void A::f(); // SemanticDC == namespace 'A'
  882.   ///                // LexicalDC == global namespace
  883.   DeclContext *getLexicalDeclContext() {
  884.     if (isInSemaDC())
  885.       return getSemanticDC();
  886.     return getMultipleDC()->LexicalDC;
  887.   }
  888.   const DeclContext *getLexicalDeclContext() const {
  889.     return const_cast<Decl*>(this)->getLexicalDeclContext();
  890.   }
  891.  
  892.   /// Determine whether this declaration is declared out of line (outside its
  893.   /// semantic context).
  894.   virtual bool isOutOfLine() const;
  895.  
  896.   /// setDeclContext - Set both the semantic and lexical DeclContext
  897.   /// to DC.
  898.   void setDeclContext(DeclContext *DC);
  899.  
  900.   void setLexicalDeclContext(DeclContext *DC);
  901.  
  902.   /// Determine whether this declaration is a templated entity (whether it is
  903.   // within the scope of a template parameter).
  904.   bool isTemplated() const;
  905.  
  906.   /// Determine the number of levels of template parameter surrounding this
  907.   /// declaration.
  908.   unsigned getTemplateDepth() const;
  909.  
  910.   /// isDefinedOutsideFunctionOrMethod - This predicate returns true if this
  911.   /// scoped decl is defined outside the current function or method.  This is
  912.   /// roughly global variables and functions, but also handles enums (which
  913.   /// could be defined inside or outside a function etc).
  914.   bool isDefinedOutsideFunctionOrMethod() const {
  915.     return getParentFunctionOrMethod() == nullptr;
  916.   }
  917.  
  918.   /// Determine whether a substitution into this declaration would occur as
  919.   /// part of a substitution into a dependent local scope. Such a substitution
  920.   /// transitively substitutes into all constructs nested within this
  921.   /// declaration.
  922.   ///
  923.   /// This recognizes non-defining declarations as well as members of local
  924.   /// classes and lambdas:
  925.   /// \code
  926.   ///     template<typename T> void foo() { void bar(); }
  927.   ///     template<typename T> void foo2() { class ABC { void bar(); }; }
  928.   ///     template<typename T> inline int x = [](){ return 0; }();
  929.   /// \endcode
  930.   bool isInLocalScopeForInstantiation() const;
  931.  
  932.   /// If this decl is defined inside a function/method/block it returns
  933.   /// the corresponding DeclContext, otherwise it returns null.
  934.   const DeclContext *
  935.   getParentFunctionOrMethod(bool LexicalParent = false) const;
  936.   DeclContext *getParentFunctionOrMethod(bool LexicalParent = false) {
  937.     return const_cast<DeclContext *>(
  938.         const_cast<const Decl *>(this)->getParentFunctionOrMethod(
  939.             LexicalParent));
  940.   }
  941.  
  942.   /// Retrieves the "canonical" declaration of the given declaration.
  943.   virtual Decl *getCanonicalDecl() { return this; }
  944.   const Decl *getCanonicalDecl() const {
  945.     return const_cast<Decl*>(this)->getCanonicalDecl();
  946.   }
  947.  
  948.   /// Whether this particular Decl is a canonical one.
  949.   bool isCanonicalDecl() const { return getCanonicalDecl() == this; }
  950.  
  951. protected:
  952.   /// Returns the next redeclaration or itself if this is the only decl.
  953.   ///
  954.   /// Decl subclasses that can be redeclared should override this method so that
  955.   /// Decl::redecl_iterator can iterate over them.
  956.   virtual Decl *getNextRedeclarationImpl() { return this; }
  957.  
  958.   /// Implementation of getPreviousDecl(), to be overridden by any
  959.   /// subclass that has a redeclaration chain.
  960.   virtual Decl *getPreviousDeclImpl() { return nullptr; }
  961.  
  962.   /// Implementation of getMostRecentDecl(), to be overridden by any
  963.   /// subclass that has a redeclaration chain.
  964.   virtual Decl *getMostRecentDeclImpl() { return this; }
  965.  
  966. public:
  967.   /// Iterates through all the redeclarations of the same decl.
  968.   class redecl_iterator {
  969.     /// Current - The current declaration.
  970.     Decl *Current = nullptr;
  971.     Decl *Starter;
  972.  
  973.   public:
  974.     using value_type = Decl *;
  975.     using reference = const value_type &;
  976.     using pointer = const value_type *;
  977.     using iterator_category = std::forward_iterator_tag;
  978.     using difference_type = std::ptrdiff_t;
  979.  
  980.     redecl_iterator() = default;
  981.     explicit redecl_iterator(Decl *C) : Current(C), Starter(C) {}
  982.  
  983.     reference operator*() const { return Current; }
  984.     value_type operator->() const { return Current; }
  985.  
  986.     redecl_iterator& operator++() {
  987.       assert(Current && "Advancing while iterator has reached end");
  988.       // Get either previous decl or latest decl.
  989.       Decl *Next = Current->getNextRedeclarationImpl();
  990.       assert(Next && "Should return next redeclaration or itself, never null!");
  991.       Current = (Next != Starter) ? Next : nullptr;
  992.       return *this;
  993.     }
  994.  
  995.     redecl_iterator operator++(int) {
  996.       redecl_iterator tmp(*this);
  997.       ++(*this);
  998.       return tmp;
  999.     }
  1000.  
  1001.     friend bool operator==(redecl_iterator x, redecl_iterator y) {
  1002.       return x.Current == y.Current;
  1003.     }
  1004.  
  1005.     friend bool operator!=(redecl_iterator x, redecl_iterator y) {
  1006.       return x.Current != y.Current;
  1007.     }
  1008.   };
  1009.  
  1010.   using redecl_range = llvm::iterator_range<redecl_iterator>;
  1011.  
  1012.   /// Returns an iterator range for all the redeclarations of the same
  1013.   /// decl. It will iterate at least once (when this decl is the only one).
  1014.   redecl_range redecls() const {
  1015.     return redecl_range(redecls_begin(), redecls_end());
  1016.   }
  1017.  
  1018.   redecl_iterator redecls_begin() const {
  1019.     return redecl_iterator(const_cast<Decl *>(this));
  1020.   }
  1021.  
  1022.   redecl_iterator redecls_end() const { return redecl_iterator(); }
  1023.  
  1024.   /// Retrieve the previous declaration that declares the same entity
  1025.   /// as this declaration, or NULL if there is no previous declaration.
  1026.   Decl *getPreviousDecl() { return getPreviousDeclImpl(); }
  1027.  
  1028.   /// Retrieve the previous declaration that declares the same entity
  1029.   /// as this declaration, or NULL if there is no previous declaration.
  1030.   const Decl *getPreviousDecl() const {
  1031.     return const_cast<Decl *>(this)->getPreviousDeclImpl();
  1032.   }
  1033.  
  1034.   /// True if this is the first declaration in its redeclaration chain.
  1035.   bool isFirstDecl() const {
  1036.     return getPreviousDecl() == nullptr;
  1037.   }
  1038.  
  1039.   /// Retrieve the most recent declaration that declares the same entity
  1040.   /// as this declaration (which may be this declaration).
  1041.   Decl *getMostRecentDecl() { return getMostRecentDeclImpl(); }
  1042.  
  1043.   /// Retrieve the most recent declaration that declares the same entity
  1044.   /// as this declaration (which may be this declaration).
  1045.   const Decl *getMostRecentDecl() const {
  1046.     return const_cast<Decl *>(this)->getMostRecentDeclImpl();
  1047.   }
  1048.  
  1049.   /// getBody - If this Decl represents a declaration for a body of code,
  1050.   ///  such as a function or method definition, this method returns the
  1051.   ///  top-level Stmt* of that body.  Otherwise this method returns null.
  1052.   virtual Stmt* getBody() const { return nullptr; }
  1053.  
  1054.   /// Returns true if this \c Decl represents a declaration for a body of
  1055.   /// code, such as a function or method definition.
  1056.   /// Note that \c hasBody can also return true if any redeclaration of this
  1057.   /// \c Decl represents a declaration for a body of code.
  1058.   virtual bool hasBody() const { return getBody() != nullptr; }
  1059.  
  1060.   /// getBodyRBrace - Gets the right brace of the body, if a body exists.
  1061.   /// This works whether the body is a CompoundStmt or a CXXTryStmt.
  1062.   SourceLocation getBodyRBrace() const;
  1063.  
  1064.   // global temp stats (until we have a per-module visitor)
  1065.   static void add(Kind k);
  1066.   static void EnableStatistics();
  1067.   static void PrintStats();
  1068.  
  1069.   /// isTemplateParameter - Determines whether this declaration is a
  1070.   /// template parameter.
  1071.   bool isTemplateParameter() const;
  1072.  
  1073.   /// isTemplateParameter - Determines whether this declaration is a
  1074.   /// template parameter pack.
  1075.   bool isTemplateParameterPack() const;
  1076.  
  1077.   /// Whether this declaration is a parameter pack.
  1078.   bool isParameterPack() const;
  1079.  
  1080.   /// returns true if this declaration is a template
  1081.   bool isTemplateDecl() const;
  1082.  
  1083.   /// Whether this declaration is a function or function template.
  1084.   bool isFunctionOrFunctionTemplate() const {
  1085.     return (DeclKind >= Decl::firstFunction &&
  1086.             DeclKind <= Decl::lastFunction) ||
  1087.            DeclKind == FunctionTemplate;
  1088.   }
  1089.  
  1090.   /// If this is a declaration that describes some template, this
  1091.   /// method returns that template declaration.
  1092.   ///
  1093.   /// Note that this returns nullptr for partial specializations, because they
  1094.   /// are not modeled as TemplateDecls. Use getDescribedTemplateParams to handle
  1095.   /// those cases.
  1096.   TemplateDecl *getDescribedTemplate() const;
  1097.  
  1098.   /// If this is a declaration that describes some template or partial
  1099.   /// specialization, this returns the corresponding template parameter list.
  1100.   const TemplateParameterList *getDescribedTemplateParams() const;
  1101.  
  1102.   /// Returns the function itself, or the templated function if this is a
  1103.   /// function template.
  1104.   FunctionDecl *getAsFunction() LLVM_READONLY;
  1105.  
  1106.   const FunctionDecl *getAsFunction() const {
  1107.     return const_cast<Decl *>(this)->getAsFunction();
  1108.   }
  1109.  
  1110.   /// Changes the namespace of this declaration to reflect that it's
  1111.   /// a function-local extern declaration.
  1112.   ///
  1113.   /// These declarations appear in the lexical context of the extern
  1114.   /// declaration, but in the semantic context of the enclosing namespace
  1115.   /// scope.
  1116.   void setLocalExternDecl() {
  1117.     Decl *Prev = getPreviousDecl();
  1118.     IdentifierNamespace &= ~IDNS_Ordinary;
  1119.  
  1120.     // It's OK for the declaration to still have the "invisible friend" flag or
  1121.     // the "conflicts with tag declarations in this scope" flag for the outer
  1122.     // scope.
  1123.     assert((IdentifierNamespace & ~(IDNS_OrdinaryFriend | IDNS_Tag)) == 0 &&
  1124.            "namespace is not ordinary");
  1125.  
  1126.     IdentifierNamespace |= IDNS_LocalExtern;
  1127.     if (Prev && Prev->getIdentifierNamespace() & IDNS_Ordinary)
  1128.       IdentifierNamespace |= IDNS_Ordinary;
  1129.   }
  1130.  
  1131.   /// Determine whether this is a block-scope declaration with linkage.
  1132.   /// This will either be a local variable declaration declared 'extern', or a
  1133.   /// local function declaration.
  1134.   bool isLocalExternDecl() const {
  1135.     return IdentifierNamespace & IDNS_LocalExtern;
  1136.   }
  1137.  
  1138.   /// Changes the namespace of this declaration to reflect that it's
  1139.   /// the object of a friend declaration.
  1140.   ///
  1141.   /// These declarations appear in the lexical context of the friending
  1142.   /// class, but in the semantic context of the actual entity.  This property
  1143.   /// applies only to a specific decl object;  other redeclarations of the
  1144.   /// same entity may not (and probably don't) share this property.
  1145.   void setObjectOfFriendDecl(bool PerformFriendInjection = false) {
  1146.     unsigned OldNS = IdentifierNamespace;
  1147.     assert((OldNS & (IDNS_Tag | IDNS_Ordinary |
  1148.                      IDNS_TagFriend | IDNS_OrdinaryFriend |
  1149.                      IDNS_LocalExtern | IDNS_NonMemberOperator)) &&
  1150.            "namespace includes neither ordinary nor tag");
  1151.     assert(!(OldNS & ~(IDNS_Tag | IDNS_Ordinary | IDNS_Type |
  1152.                        IDNS_TagFriend | IDNS_OrdinaryFriend |
  1153.                        IDNS_LocalExtern | IDNS_NonMemberOperator)) &&
  1154.            "namespace includes other than ordinary or tag");
  1155.  
  1156.     Decl *Prev = getPreviousDecl();
  1157.     IdentifierNamespace &= ~(IDNS_Ordinary | IDNS_Tag | IDNS_Type);
  1158.  
  1159.     if (OldNS & (IDNS_Tag | IDNS_TagFriend)) {
  1160.       IdentifierNamespace |= IDNS_TagFriend;
  1161.       if (PerformFriendInjection ||
  1162.           (Prev && Prev->getIdentifierNamespace() & IDNS_Tag))
  1163.         IdentifierNamespace |= IDNS_Tag | IDNS_Type;
  1164.     }
  1165.  
  1166.     if (OldNS & (IDNS_Ordinary | IDNS_OrdinaryFriend |
  1167.                  IDNS_LocalExtern | IDNS_NonMemberOperator)) {
  1168.       IdentifierNamespace |= IDNS_OrdinaryFriend;
  1169.       if (PerformFriendInjection ||
  1170.           (Prev && Prev->getIdentifierNamespace() & IDNS_Ordinary))
  1171.         IdentifierNamespace |= IDNS_Ordinary;
  1172.     }
  1173.   }
  1174.  
  1175.   enum FriendObjectKind {
  1176.     FOK_None,      ///< Not a friend object.
  1177.     FOK_Declared,  ///< A friend of a previously-declared entity.
  1178.     FOK_Undeclared ///< A friend of a previously-undeclared entity.
  1179.   };
  1180.  
  1181.   /// Determines whether this declaration is the object of a
  1182.   /// friend declaration and, if so, what kind.
  1183.   ///
  1184.   /// There is currently no direct way to find the associated FriendDecl.
  1185.   FriendObjectKind getFriendObjectKind() const {
  1186.     unsigned mask =
  1187.         (IdentifierNamespace & (IDNS_TagFriend | IDNS_OrdinaryFriend));
  1188.     if (!mask) return FOK_None;
  1189.     return (IdentifierNamespace & (IDNS_Tag | IDNS_Ordinary) ? FOK_Declared
  1190.                                                              : FOK_Undeclared);
  1191.   }
  1192.  
  1193.   /// Specifies that this declaration is a C++ overloaded non-member.
  1194.   void setNonMemberOperator() {
  1195.     assert(getKind() == Function || getKind() == FunctionTemplate);
  1196.     assert((IdentifierNamespace & IDNS_Ordinary) &&
  1197.            "visible non-member operators should be in ordinary namespace");
  1198.     IdentifierNamespace |= IDNS_NonMemberOperator;
  1199.   }
  1200.  
  1201.   static bool classofKind(Kind K) { return true; }
  1202.   static DeclContext *castToDeclContext(const Decl *);
  1203.   static Decl *castFromDeclContext(const DeclContext *);
  1204.  
  1205.   void print(raw_ostream &Out, unsigned Indentation = 0,
  1206.              bool PrintInstantiation = false) const;
  1207.   void print(raw_ostream &Out, const PrintingPolicy &Policy,
  1208.              unsigned Indentation = 0, bool PrintInstantiation = false) const;
  1209.   static void printGroup(Decl** Begin, unsigned NumDecls,
  1210.                          raw_ostream &Out, const PrintingPolicy &Policy,
  1211.                          unsigned Indentation = 0);
  1212.  
  1213.   // Debuggers don't usually respect default arguments.
  1214.   void dump() const;
  1215.  
  1216.   // Same as dump(), but forces color printing.
  1217.   void dumpColor() const;
  1218.  
  1219.   void dump(raw_ostream &Out, bool Deserialize = false,
  1220.             ASTDumpOutputFormat OutputFormat = ADOF_Default) const;
  1221.  
  1222.   /// \return Unique reproducible object identifier
  1223.   int64_t getID() const;
  1224.  
  1225.   /// Looks through the Decl's underlying type to extract a FunctionType
  1226.   /// when possible. Will return null if the type underlying the Decl does not
  1227.   /// have a FunctionType.
  1228.   const FunctionType *getFunctionType(bool BlocksToo = true) const;
  1229.  
  1230. private:
  1231.   void setAttrsImpl(const AttrVec& Attrs, ASTContext &Ctx);
  1232.   void setDeclContextsImpl(DeclContext *SemaDC, DeclContext *LexicalDC,
  1233.                            ASTContext &Ctx);
  1234.  
  1235. protected:
  1236.   ASTMutationListener *getASTMutationListener() const;
  1237. };
  1238.  
  1239. /// Determine whether two declarations declare the same entity.
  1240. inline bool declaresSameEntity(const Decl *D1, const Decl *D2) {
  1241.   if (!D1 || !D2)
  1242.     return false;
  1243.  
  1244.   if (D1 == D2)
  1245.     return true;
  1246.  
  1247.   return D1->getCanonicalDecl() == D2->getCanonicalDecl();
  1248. }
  1249.  
  1250. /// PrettyStackTraceDecl - If a crash occurs, indicate that it happened when
  1251. /// doing something to a specific decl.
  1252. class PrettyStackTraceDecl : public llvm::PrettyStackTraceEntry {
  1253.   const Decl *TheDecl;
  1254.   SourceLocation Loc;
  1255.   SourceManager &SM;
  1256.   const char *Message;
  1257.  
  1258. public:
  1259.   PrettyStackTraceDecl(const Decl *theDecl, SourceLocation L,
  1260.                        SourceManager &sm, const char *Msg)
  1261.       : TheDecl(theDecl), Loc(L), SM(sm), Message(Msg) {}
  1262.  
  1263.   void print(raw_ostream &OS) const override;
  1264. };
  1265. } // namespace clang
  1266.  
  1267. // Required to determine the layout of the PointerUnion<NamedDecl*> before
  1268. // seeing the NamedDecl definition being first used in DeclListNode::operator*.
  1269. namespace llvm {
  1270.   template <> struct PointerLikeTypeTraits<::clang::NamedDecl *> {
  1271.     static inline void *getAsVoidPointer(::clang::NamedDecl *P) { return P; }
  1272.     static inline ::clang::NamedDecl *getFromVoidPointer(void *P) {
  1273.       return static_cast<::clang::NamedDecl *>(P);
  1274.     }
  1275.     static constexpr int NumLowBitsAvailable = 3;
  1276.   };
  1277. }
  1278.  
  1279. namespace clang {
  1280. /// A list storing NamedDecls in the lookup tables.
  1281. class DeclListNode {
  1282.   friend class ASTContext; // allocate, deallocate nodes.
  1283.   friend class StoredDeclsList;
  1284. public:
  1285.   using Decls = llvm::PointerUnion<NamedDecl*, DeclListNode*>;
  1286.   class iterator {
  1287.     friend class DeclContextLookupResult;
  1288.     friend class StoredDeclsList;
  1289.  
  1290.     Decls Ptr;
  1291.     iterator(Decls Node) : Ptr(Node) { }
  1292.   public:
  1293.     using difference_type = ptrdiff_t;
  1294.     using value_type = NamedDecl*;
  1295.     using pointer = void;
  1296.     using reference = value_type;
  1297.     using iterator_category = std::forward_iterator_tag;
  1298.  
  1299.     iterator() = default;
  1300.  
  1301.     reference operator*() const {
  1302.       assert(Ptr && "dereferencing end() iterator");
  1303.       if (DeclListNode *CurNode = Ptr.dyn_cast<DeclListNode*>())
  1304.         return CurNode->D;
  1305.       return Ptr.get<NamedDecl*>();
  1306.     }
  1307.     void operator->() const { } // Unsupported.
  1308.     bool operator==(const iterator &X) const { return Ptr == X.Ptr; }
  1309.     bool operator!=(const iterator &X) const { return Ptr != X.Ptr; }
  1310.     inline iterator &operator++() { // ++It
  1311.       assert(!Ptr.isNull() && "Advancing empty iterator");
  1312.  
  1313.       if (DeclListNode *CurNode = Ptr.dyn_cast<DeclListNode*>())
  1314.         Ptr = CurNode->Rest;
  1315.       else
  1316.         Ptr = nullptr;
  1317.       return *this;
  1318.     }
  1319.     iterator operator++(int) { // It++
  1320.       iterator temp = *this;
  1321.       ++(*this);
  1322.       return temp;
  1323.     }
  1324.     // Enables the pattern for (iterator I =..., E = I.end(); I != E; ++I)
  1325.     iterator end() { return iterator(); }
  1326.   };
  1327. private:
  1328.   NamedDecl *D = nullptr;
  1329.   Decls Rest = nullptr;
  1330.   DeclListNode(NamedDecl *ND) : D(ND) {}
  1331. };
  1332.  
  1333. /// The results of name lookup within a DeclContext.
  1334. class DeclContextLookupResult {
  1335.   using Decls = DeclListNode::Decls;
  1336.  
  1337.   /// When in collection form, this is what the Data pointer points to.
  1338.   Decls Result;
  1339.  
  1340. public:
  1341.   DeclContextLookupResult() = default;
  1342.   DeclContextLookupResult(Decls Result) : Result(Result) {}
  1343.  
  1344.   using iterator = DeclListNode::iterator;
  1345.   using const_iterator = iterator;
  1346.   using reference = iterator::reference;
  1347.  
  1348.   iterator begin() { return iterator(Result); }
  1349.   iterator end() { return iterator(); }
  1350.   const_iterator begin() const {
  1351.     return const_cast<DeclContextLookupResult*>(this)->begin();
  1352.   }
  1353.   const_iterator end() const { return iterator(); }
  1354.  
  1355.   bool empty() const { return Result.isNull();  }
  1356.   bool isSingleResult() const { return Result.dyn_cast<NamedDecl*>(); }
  1357.   reference front() const { return *begin(); }
  1358.  
  1359.   // Find the first declaration of the given type in the list. Note that this
  1360.   // is not in general the earliest-declared declaration, and should only be
  1361.   // used when it's not possible for there to be more than one match or where
  1362.   // it doesn't matter which one is found.
  1363.   template<class T> T *find_first() const {
  1364.     for (auto *D : *this)
  1365.       if (T *Decl = dyn_cast<T>(D))
  1366.         return Decl;
  1367.  
  1368.     return nullptr;
  1369.   }
  1370. };
  1371.  
  1372. /// DeclContext - This is used only as base class of specific decl types that
  1373. /// can act as declaration contexts. These decls are (only the top classes
  1374. /// that directly derive from DeclContext are mentioned, not their subclasses):
  1375. ///
  1376. ///   TranslationUnitDecl
  1377. ///   ExternCContext
  1378. ///   NamespaceDecl
  1379. ///   TagDecl
  1380. ///   OMPDeclareReductionDecl
  1381. ///   OMPDeclareMapperDecl
  1382. ///   FunctionDecl
  1383. ///   ObjCMethodDecl
  1384. ///   ObjCContainerDecl
  1385. ///   LinkageSpecDecl
  1386. ///   ExportDecl
  1387. ///   BlockDecl
  1388. ///   CapturedDecl
  1389. class DeclContext {
  1390.   /// For makeDeclVisibleInContextImpl
  1391.   friend class ASTDeclReader;
  1392.   /// For reconcileExternalVisibleStorage, CreateStoredDeclsMap,
  1393.   /// hasNeedToReconcileExternalVisibleStorage
  1394.   friend class ExternalASTSource;
  1395.   /// For CreateStoredDeclsMap
  1396.   friend class DependentDiagnostic;
  1397.   /// For hasNeedToReconcileExternalVisibleStorage,
  1398.   /// hasLazyLocalLexicalLookups, hasLazyExternalLexicalLookups
  1399.   friend class ASTWriter;
  1400.  
  1401.   // We use uint64_t in the bit-fields below since some bit-fields
  1402.   // cross the unsigned boundary and this breaks the packing.
  1403.  
  1404.   /// Stores the bits used by DeclContext.
  1405.   /// If modified NumDeclContextBit, the ctor of DeclContext and the accessor
  1406.   /// methods in DeclContext should be updated appropriately.
  1407.   class DeclContextBitfields {
  1408.     friend class DeclContext;
  1409.     /// DeclKind - This indicates which class this is.
  1410.     uint64_t DeclKind : 7;
  1411.  
  1412.     /// Whether this declaration context also has some external
  1413.     /// storage that contains additional declarations that are lexically
  1414.     /// part of this context.
  1415.     mutable uint64_t ExternalLexicalStorage : 1;
  1416.  
  1417.     /// Whether this declaration context also has some external
  1418.     /// storage that contains additional declarations that are visible
  1419.     /// in this context.
  1420.     mutable uint64_t ExternalVisibleStorage : 1;
  1421.  
  1422.     /// Whether this declaration context has had externally visible
  1423.     /// storage added since the last lookup. In this case, \c LookupPtr's
  1424.     /// invariant may not hold and needs to be fixed before we perform
  1425.     /// another lookup.
  1426.     mutable uint64_t NeedToReconcileExternalVisibleStorage : 1;
  1427.  
  1428.     /// If \c true, this context may have local lexical declarations
  1429.     /// that are missing from the lookup table.
  1430.     mutable uint64_t HasLazyLocalLexicalLookups : 1;
  1431.  
  1432.     /// If \c true, the external source may have lexical declarations
  1433.     /// that are missing from the lookup table.
  1434.     mutable uint64_t HasLazyExternalLexicalLookups : 1;
  1435.  
  1436.     /// If \c true, lookups should only return identifier from
  1437.     /// DeclContext scope (for example TranslationUnit). Used in
  1438.     /// LookupQualifiedName()
  1439.     mutable uint64_t UseQualifiedLookup : 1;
  1440.   };
  1441.  
  1442.   /// Number of bits in DeclContextBitfields.
  1443.   enum { NumDeclContextBits = 13 };
  1444.  
  1445.   /// Stores the bits used by TagDecl.
  1446.   /// If modified NumTagDeclBits and the accessor
  1447.   /// methods in TagDecl should be updated appropriately.
  1448.   class TagDeclBitfields {
  1449.     friend class TagDecl;
  1450.     /// For the bits in DeclContextBitfields
  1451.     uint64_t : NumDeclContextBits;
  1452.  
  1453.     /// The TagKind enum.
  1454.     uint64_t TagDeclKind : 3;
  1455.  
  1456.     /// True if this is a definition ("struct foo {};"), false if it is a
  1457.     /// declaration ("struct foo;").  It is not considered a definition
  1458.     /// until the definition has been fully processed.
  1459.     uint64_t IsCompleteDefinition : 1;
  1460.  
  1461.     /// True if this is currently being defined.
  1462.     uint64_t IsBeingDefined : 1;
  1463.  
  1464.     /// True if this tag declaration is "embedded" (i.e., defined or declared
  1465.     /// for the very first time) in the syntax of a declarator.
  1466.     uint64_t IsEmbeddedInDeclarator : 1;
  1467.  
  1468.     /// True if this tag is free standing, e.g. "struct foo;".
  1469.     uint64_t IsFreeStanding : 1;
  1470.  
  1471.     /// Indicates whether it is possible for declarations of this kind
  1472.     /// to have an out-of-date definition.
  1473.     ///
  1474.     /// This option is only enabled when modules are enabled.
  1475.     uint64_t MayHaveOutOfDateDef : 1;
  1476.  
  1477.     /// Has the full definition of this type been required by a use somewhere in
  1478.     /// the TU.
  1479.     uint64_t IsCompleteDefinitionRequired : 1;
  1480.  
  1481.     /// Whether this tag is a definition which was demoted due to
  1482.     /// a module merge.
  1483.     uint64_t IsThisDeclarationADemotedDefinition : 1;
  1484.   };
  1485.  
  1486.   /// Number of non-inherited bits in TagDeclBitfields.
  1487.   enum { NumTagDeclBits = 10 };
  1488.  
  1489.   /// Stores the bits used by EnumDecl.
  1490.   /// If modified NumEnumDeclBit and the accessor
  1491.   /// methods in EnumDecl should be updated appropriately.
  1492.   class EnumDeclBitfields {
  1493.     friend class EnumDecl;
  1494.     /// For the bits in DeclContextBitfields.
  1495.     uint64_t : NumDeclContextBits;
  1496.     /// For the bits in TagDeclBitfields.
  1497.     uint64_t : NumTagDeclBits;
  1498.  
  1499.     /// Width in bits required to store all the non-negative
  1500.     /// enumerators of this enum.
  1501.     uint64_t NumPositiveBits : 8;
  1502.  
  1503.     /// Width in bits required to store all the negative
  1504.     /// enumerators of this enum.
  1505.     uint64_t NumNegativeBits : 8;
  1506.  
  1507.     /// True if this tag declaration is a scoped enumeration. Only
  1508.     /// possible in C++11 mode.
  1509.     uint64_t IsScoped : 1;
  1510.  
  1511.     /// If this tag declaration is a scoped enum,
  1512.     /// then this is true if the scoped enum was declared using the class
  1513.     /// tag, false if it was declared with the struct tag. No meaning is
  1514.     /// associated if this tag declaration is not a scoped enum.
  1515.     uint64_t IsScopedUsingClassTag : 1;
  1516.  
  1517.     /// True if this is an enumeration with fixed underlying type. Only
  1518.     /// possible in C++11, Microsoft extensions, or Objective C mode.
  1519.     uint64_t IsFixed : 1;
  1520.  
  1521.     /// True if a valid hash is stored in ODRHash.
  1522.     uint64_t HasODRHash : 1;
  1523.   };
  1524.  
  1525.   /// Number of non-inherited bits in EnumDeclBitfields.
  1526.   enum { NumEnumDeclBits = 20 };
  1527.  
  1528.   /// Stores the bits used by RecordDecl.
  1529.   /// If modified NumRecordDeclBits and the accessor
  1530.   /// methods in RecordDecl should be updated appropriately.
  1531.   class RecordDeclBitfields {
  1532.     friend class RecordDecl;
  1533.     /// For the bits in DeclContextBitfields.
  1534.     uint64_t : NumDeclContextBits;
  1535.     /// For the bits in TagDeclBitfields.
  1536.     uint64_t : NumTagDeclBits;
  1537.  
  1538.     /// This is true if this struct ends with a flexible
  1539.     /// array member (e.g. int X[]) or if this union contains a struct that does.
  1540.     /// If so, this cannot be contained in arrays or other structs as a member.
  1541.     uint64_t HasFlexibleArrayMember : 1;
  1542.  
  1543.     /// Whether this is the type of an anonymous struct or union.
  1544.     uint64_t AnonymousStructOrUnion : 1;
  1545.  
  1546.     /// This is true if this struct has at least one member
  1547.     /// containing an Objective-C object pointer type.
  1548.     uint64_t HasObjectMember : 1;
  1549.  
  1550.     /// This is true if struct has at least one member of
  1551.     /// 'volatile' type.
  1552.     uint64_t HasVolatileMember : 1;
  1553.  
  1554.     /// Whether the field declarations of this record have been loaded
  1555.     /// from external storage. To avoid unnecessary deserialization of
  1556.     /// methods/nested types we allow deserialization of just the fields
  1557.     /// when needed.
  1558.     mutable uint64_t LoadedFieldsFromExternalStorage : 1;
  1559.  
  1560.     /// Basic properties of non-trivial C structs.
  1561.     uint64_t NonTrivialToPrimitiveDefaultInitialize : 1;
  1562.     uint64_t NonTrivialToPrimitiveCopy : 1;
  1563.     uint64_t NonTrivialToPrimitiveDestroy : 1;
  1564.  
  1565.     /// The following bits indicate whether this is or contains a C union that
  1566.     /// is non-trivial to default-initialize, destruct, or copy. These bits
  1567.     /// imply the associated basic non-triviality predicates declared above.
  1568.     uint64_t HasNonTrivialToPrimitiveDefaultInitializeCUnion : 1;
  1569.     uint64_t HasNonTrivialToPrimitiveDestructCUnion : 1;
  1570.     uint64_t HasNonTrivialToPrimitiveCopyCUnion : 1;
  1571.  
  1572.     /// Indicates whether this struct is destroyed in the callee.
  1573.     uint64_t ParamDestroyedInCallee : 1;
  1574.  
  1575.     /// Represents the way this type is passed to a function.
  1576.     uint64_t ArgPassingRestrictions : 2;
  1577.  
  1578.     /// Indicates whether this struct has had its field layout randomized.
  1579.     uint64_t IsRandomized : 1;
  1580.  
  1581.     /// True if a valid hash is stored in ODRHash. This should shave off some
  1582.     /// extra storage and prevent CXXRecordDecl to store unused bits.
  1583.     uint64_t ODRHash : 26;
  1584.   };
  1585.  
  1586.   /// Number of non-inherited bits in RecordDeclBitfields.
  1587.   enum { NumRecordDeclBits = 41 };
  1588.  
  1589.   /// Stores the bits used by OMPDeclareReductionDecl.
  1590.   /// If modified NumOMPDeclareReductionDeclBits and the accessor
  1591.   /// methods in OMPDeclareReductionDecl should be updated appropriately.
  1592.   class OMPDeclareReductionDeclBitfields {
  1593.     friend class OMPDeclareReductionDecl;
  1594.     /// For the bits in DeclContextBitfields
  1595.     uint64_t : NumDeclContextBits;
  1596.  
  1597.     /// Kind of initializer,
  1598.     /// function call or omp_priv<init_expr> initializtion.
  1599.     uint64_t InitializerKind : 2;
  1600.   };
  1601.  
  1602.   /// Number of non-inherited bits in OMPDeclareReductionDeclBitfields.
  1603.   enum { NumOMPDeclareReductionDeclBits = 2 };
  1604.  
  1605.   /// Stores the bits used by FunctionDecl.
  1606.   /// If modified NumFunctionDeclBits and the accessor
  1607.   /// methods in FunctionDecl and CXXDeductionGuideDecl
  1608.   /// (for IsCopyDeductionCandidate) should be updated appropriately.
  1609.   class FunctionDeclBitfields {
  1610.     friend class FunctionDecl;
  1611.     /// For IsCopyDeductionCandidate
  1612.     friend class CXXDeductionGuideDecl;
  1613.     /// For the bits in DeclContextBitfields.
  1614.     uint64_t : NumDeclContextBits;
  1615.  
  1616.     uint64_t SClass : 3;
  1617.     uint64_t IsInline : 1;
  1618.     uint64_t IsInlineSpecified : 1;
  1619.  
  1620.     uint64_t IsVirtualAsWritten : 1;
  1621.     uint64_t IsPure : 1;
  1622.     uint64_t HasInheritedPrototype : 1;
  1623.     uint64_t HasWrittenPrototype : 1;
  1624.     uint64_t IsDeleted : 1;
  1625.     /// Used by CXXMethodDecl
  1626.     uint64_t IsTrivial : 1;
  1627.  
  1628.     /// This flag indicates whether this function is trivial for the purpose of
  1629.     /// calls. This is meaningful only when this function is a copy/move
  1630.     /// constructor or a destructor.
  1631.     uint64_t IsTrivialForCall : 1;
  1632.  
  1633.     uint64_t IsDefaulted : 1;
  1634.     uint64_t IsExplicitlyDefaulted : 1;
  1635.     uint64_t HasDefaultedFunctionInfo : 1;
  1636.  
  1637.     /// For member functions of complete types, whether this is an ineligible
  1638.     /// special member function or an unselected destructor. See
  1639.     /// [class.mem.special].
  1640.     uint64_t IsIneligibleOrNotSelected : 1;
  1641.  
  1642.     uint64_t HasImplicitReturnZero : 1;
  1643.     uint64_t IsLateTemplateParsed : 1;
  1644.  
  1645.     /// Kind of contexpr specifier as defined by ConstexprSpecKind.
  1646.     uint64_t ConstexprKind : 2;
  1647.     uint64_t InstantiationIsPending : 1;
  1648.  
  1649.     /// Indicates if the function uses __try.
  1650.     uint64_t UsesSEHTry : 1;
  1651.  
  1652.     /// Indicates if the function was a definition
  1653.     /// but its body was skipped.
  1654.     uint64_t HasSkippedBody : 1;
  1655.  
  1656.     /// Indicates if the function declaration will
  1657.     /// have a body, once we're done parsing it.
  1658.     uint64_t WillHaveBody : 1;
  1659.  
  1660.     /// Indicates that this function is a multiversioned
  1661.     /// function using attribute 'target'.
  1662.     uint64_t IsMultiVersion : 1;
  1663.  
  1664.     /// [C++17] Only used by CXXDeductionGuideDecl. Indicates that
  1665.     /// the Deduction Guide is the implicitly generated 'copy
  1666.     /// deduction candidate' (is used during overload resolution).
  1667.     uint64_t IsCopyDeductionCandidate : 1;
  1668.  
  1669.     /// Store the ODRHash after first calculation.
  1670.     uint64_t HasODRHash : 1;
  1671.  
  1672.     /// Indicates if the function uses Floating Point Constrained Intrinsics
  1673.     uint64_t UsesFPIntrin : 1;
  1674.  
  1675.     // Indicates this function is a constrained friend, where the constraint
  1676.     // refers to an enclosing template for hte purposes of [temp.friend]p9.
  1677.     uint64_t FriendConstraintRefersToEnclosingTemplate : 1;
  1678.   };
  1679.  
  1680.   /// Number of non-inherited bits in FunctionDeclBitfields.
  1681.   enum { NumFunctionDeclBits = 29 };
  1682.  
  1683.   /// Stores the bits used by CXXConstructorDecl. If modified
  1684.   /// NumCXXConstructorDeclBits and the accessor
  1685.   /// methods in CXXConstructorDecl should be updated appropriately.
  1686.   class CXXConstructorDeclBitfields {
  1687.     friend class CXXConstructorDecl;
  1688.     /// For the bits in DeclContextBitfields.
  1689.     uint64_t : NumDeclContextBits;
  1690.     /// For the bits in FunctionDeclBitfields.
  1691.     uint64_t : NumFunctionDeclBits;
  1692.  
  1693.     /// 22 bits to fit in the remaining available space.
  1694.     /// Note that this makes CXXConstructorDeclBitfields take
  1695.     /// exactly 64 bits and thus the width of NumCtorInitializers
  1696.     /// will need to be shrunk if some bit is added to NumDeclContextBitfields,
  1697.     /// NumFunctionDeclBitfields or CXXConstructorDeclBitfields.
  1698.     uint64_t NumCtorInitializers : 19;
  1699.     uint64_t IsInheritingConstructor : 1;
  1700.  
  1701.     /// Whether this constructor has a trail-allocated explicit specifier.
  1702.     uint64_t HasTrailingExplicitSpecifier : 1;
  1703.     /// If this constructor does't have a trail-allocated explicit specifier.
  1704.     /// Whether this constructor is explicit specified.
  1705.     uint64_t IsSimpleExplicit : 1;
  1706.   };
  1707.  
  1708.   /// Number of non-inherited bits in CXXConstructorDeclBitfields.
  1709.   enum {
  1710.     NumCXXConstructorDeclBits = 64 - NumDeclContextBits - NumFunctionDeclBits
  1711.   };
  1712.  
  1713.   /// Stores the bits used by ObjCMethodDecl.
  1714.   /// If modified NumObjCMethodDeclBits and the accessor
  1715.   /// methods in ObjCMethodDecl should be updated appropriately.
  1716.   class ObjCMethodDeclBitfields {
  1717.     friend class ObjCMethodDecl;
  1718.  
  1719.     /// For the bits in DeclContextBitfields.
  1720.     uint64_t : NumDeclContextBits;
  1721.  
  1722.     /// The conventional meaning of this method; an ObjCMethodFamily.
  1723.     /// This is not serialized; instead, it is computed on demand and
  1724.     /// cached.
  1725.     mutable uint64_t Family : ObjCMethodFamilyBitWidth;
  1726.  
  1727.     /// instance (true) or class (false) method.
  1728.     uint64_t IsInstance : 1;
  1729.     uint64_t IsVariadic : 1;
  1730.  
  1731.     /// True if this method is the getter or setter for an explicit property.
  1732.     uint64_t IsPropertyAccessor : 1;
  1733.  
  1734.     /// True if this method is a synthesized property accessor stub.
  1735.     uint64_t IsSynthesizedAccessorStub : 1;
  1736.  
  1737.     /// Method has a definition.
  1738.     uint64_t IsDefined : 1;
  1739.  
  1740.     /// Method redeclaration in the same interface.
  1741.     uint64_t IsRedeclaration : 1;
  1742.  
  1743.     /// Is redeclared in the same interface.
  1744.     mutable uint64_t HasRedeclaration : 1;
  1745.  
  1746.     /// \@required/\@optional
  1747.     uint64_t DeclImplementation : 2;
  1748.  
  1749.     /// in, inout, etc.
  1750.     uint64_t objcDeclQualifier : 7;
  1751.  
  1752.     /// Indicates whether this method has a related result type.
  1753.     uint64_t RelatedResultType : 1;
  1754.  
  1755.     /// Whether the locations of the selector identifiers are in a
  1756.     /// "standard" position, a enum SelectorLocationsKind.
  1757.     uint64_t SelLocsKind : 2;
  1758.  
  1759.     /// Whether this method overrides any other in the class hierarchy.
  1760.     ///
  1761.     /// A method is said to override any method in the class's
  1762.     /// base classes, its protocols, or its categories' protocols, that has
  1763.     /// the same selector and is of the same kind (class or instance).
  1764.     /// A method in an implementation is not considered as overriding the same
  1765.     /// method in the interface or its categories.
  1766.     uint64_t IsOverriding : 1;
  1767.  
  1768.     /// Indicates if the method was a definition but its body was skipped.
  1769.     uint64_t HasSkippedBody : 1;
  1770.   };
  1771.  
  1772.   /// Number of non-inherited bits in ObjCMethodDeclBitfields.
  1773.   enum { NumObjCMethodDeclBits = 24 };
  1774.  
  1775.   /// Stores the bits used by ObjCContainerDecl.
  1776.   /// If modified NumObjCContainerDeclBits and the accessor
  1777.   /// methods in ObjCContainerDecl should be updated appropriately.
  1778.   class ObjCContainerDeclBitfields {
  1779.     friend class ObjCContainerDecl;
  1780.     /// For the bits in DeclContextBitfields
  1781.     uint32_t : NumDeclContextBits;
  1782.  
  1783.     // Not a bitfield but this saves space.
  1784.     // Note that ObjCContainerDeclBitfields is full.
  1785.     SourceLocation AtStart;
  1786.   };
  1787.  
  1788.   /// Number of non-inherited bits in ObjCContainerDeclBitfields.
  1789.   /// Note that here we rely on the fact that SourceLocation is 32 bits
  1790.   /// wide. We check this with the static_assert in the ctor of DeclContext.
  1791.   enum { NumObjCContainerDeclBits = 64 - NumDeclContextBits };
  1792.  
  1793.   /// Stores the bits used by LinkageSpecDecl.
  1794.   /// If modified NumLinkageSpecDeclBits and the accessor
  1795.   /// methods in LinkageSpecDecl should be updated appropriately.
  1796.   class LinkageSpecDeclBitfields {
  1797.     friend class LinkageSpecDecl;
  1798.     /// For the bits in DeclContextBitfields.
  1799.     uint64_t : NumDeclContextBits;
  1800.  
  1801.     /// The language for this linkage specification with values
  1802.     /// in the enum LinkageSpecDecl::LanguageIDs.
  1803.     uint64_t Language : 3;
  1804.  
  1805.     /// True if this linkage spec has braces.
  1806.     /// This is needed so that hasBraces() returns the correct result while the
  1807.     /// linkage spec body is being parsed.  Once RBraceLoc has been set this is
  1808.     /// not used, so it doesn't need to be serialized.
  1809.     uint64_t HasBraces : 1;
  1810.   };
  1811.  
  1812.   /// Number of non-inherited bits in LinkageSpecDeclBitfields.
  1813.   enum { NumLinkageSpecDeclBits = 4 };
  1814.  
  1815.   /// Stores the bits used by BlockDecl.
  1816.   /// If modified NumBlockDeclBits and the accessor
  1817.   /// methods in BlockDecl should be updated appropriately.
  1818.   class BlockDeclBitfields {
  1819.     friend class BlockDecl;
  1820.     /// For the bits in DeclContextBitfields.
  1821.     uint64_t : NumDeclContextBits;
  1822.  
  1823.     uint64_t IsVariadic : 1;
  1824.     uint64_t CapturesCXXThis : 1;
  1825.     uint64_t BlockMissingReturnType : 1;
  1826.     uint64_t IsConversionFromLambda : 1;
  1827.  
  1828.     /// A bit that indicates this block is passed directly to a function as a
  1829.     /// non-escaping parameter.
  1830.     uint64_t DoesNotEscape : 1;
  1831.  
  1832.     /// A bit that indicates whether it's possible to avoid coying this block to
  1833.     /// the heap when it initializes or is assigned to a local variable with
  1834.     /// automatic storage.
  1835.     uint64_t CanAvoidCopyToHeap : 1;
  1836.   };
  1837.  
  1838.   /// Number of non-inherited bits in BlockDeclBitfields.
  1839.   enum { NumBlockDeclBits = 5 };
  1840.  
  1841.   /// Pointer to the data structure used to lookup declarations
  1842.   /// within this context (or a DependentStoredDeclsMap if this is a
  1843.   /// dependent context). We maintain the invariant that, if the map
  1844.   /// contains an entry for a DeclarationName (and we haven't lazily
  1845.   /// omitted anything), then it contains all relevant entries for that
  1846.   /// name (modulo the hasExternalDecls() flag).
  1847.   mutable StoredDeclsMap *LookupPtr = nullptr;
  1848.  
  1849. protected:
  1850.   /// This anonymous union stores the bits belonging to DeclContext and classes
  1851.   /// deriving from it. The goal is to use otherwise wasted
  1852.   /// space in DeclContext to store data belonging to derived classes.
  1853.   /// The space saved is especially significient when pointers are aligned
  1854.   /// to 8 bytes. In this case due to alignment requirements we have a
  1855.   /// little less than 8 bytes free in DeclContext which we can use.
  1856.   /// We check that none of the classes in this union is larger than
  1857.   /// 8 bytes with static_asserts in the ctor of DeclContext.
  1858.   union {
  1859.     DeclContextBitfields DeclContextBits;
  1860.     TagDeclBitfields TagDeclBits;
  1861.     EnumDeclBitfields EnumDeclBits;
  1862.     RecordDeclBitfields RecordDeclBits;
  1863.     OMPDeclareReductionDeclBitfields OMPDeclareReductionDeclBits;
  1864.     FunctionDeclBitfields FunctionDeclBits;
  1865.     CXXConstructorDeclBitfields CXXConstructorDeclBits;
  1866.     ObjCMethodDeclBitfields ObjCMethodDeclBits;
  1867.     ObjCContainerDeclBitfields ObjCContainerDeclBits;
  1868.     LinkageSpecDeclBitfields LinkageSpecDeclBits;
  1869.     BlockDeclBitfields BlockDeclBits;
  1870.  
  1871.     static_assert(sizeof(DeclContextBitfields) <= 8,
  1872.                   "DeclContextBitfields is larger than 8 bytes!");
  1873.     static_assert(sizeof(TagDeclBitfields) <= 8,
  1874.                   "TagDeclBitfields is larger than 8 bytes!");
  1875.     static_assert(sizeof(EnumDeclBitfields) <= 8,
  1876.                   "EnumDeclBitfields is larger than 8 bytes!");
  1877.     static_assert(sizeof(RecordDeclBitfields) <= 8,
  1878.                   "RecordDeclBitfields is larger than 8 bytes!");
  1879.     static_assert(sizeof(OMPDeclareReductionDeclBitfields) <= 8,
  1880.                   "OMPDeclareReductionDeclBitfields is larger than 8 bytes!");
  1881.     static_assert(sizeof(FunctionDeclBitfields) <= 8,
  1882.                   "FunctionDeclBitfields is larger than 8 bytes!");
  1883.     static_assert(sizeof(CXXConstructorDeclBitfields) <= 8,
  1884.                   "CXXConstructorDeclBitfields is larger than 8 bytes!");
  1885.     static_assert(sizeof(ObjCMethodDeclBitfields) <= 8,
  1886.                   "ObjCMethodDeclBitfields is larger than 8 bytes!");
  1887.     static_assert(sizeof(ObjCContainerDeclBitfields) <= 8,
  1888.                   "ObjCContainerDeclBitfields is larger than 8 bytes!");
  1889.     static_assert(sizeof(LinkageSpecDeclBitfields) <= 8,
  1890.                   "LinkageSpecDeclBitfields is larger than 8 bytes!");
  1891.     static_assert(sizeof(BlockDeclBitfields) <= 8,
  1892.                   "BlockDeclBitfields is larger than 8 bytes!");
  1893.   };
  1894.  
  1895.   /// FirstDecl - The first declaration stored within this declaration
  1896.   /// context.
  1897.   mutable Decl *FirstDecl = nullptr;
  1898.  
  1899.   /// LastDecl - The last declaration stored within this declaration
  1900.   /// context. FIXME: We could probably cache this value somewhere
  1901.   /// outside of the DeclContext, to reduce the size of DeclContext by
  1902.   /// another pointer.
  1903.   mutable Decl *LastDecl = nullptr;
  1904.  
  1905.   /// Build up a chain of declarations.
  1906.   ///
  1907.   /// \returns the first/last pair of declarations.
  1908.   static std::pair<Decl *, Decl *>
  1909.   BuildDeclChain(ArrayRef<Decl*> Decls, bool FieldsAlreadyLoaded);
  1910.  
  1911.   DeclContext(Decl::Kind K);
  1912.  
  1913. public:
  1914.   ~DeclContext();
  1915.  
  1916.   // For use when debugging; hasValidDeclKind() will always return true for
  1917.   // a correctly constructed object within its lifetime.
  1918.   bool hasValidDeclKind() const;
  1919.  
  1920.   Decl::Kind getDeclKind() const {
  1921.     return static_cast<Decl::Kind>(DeclContextBits.DeclKind);
  1922.   }
  1923.  
  1924.   const char *getDeclKindName() const;
  1925.  
  1926.   /// getParent - Returns the containing DeclContext.
  1927.   DeclContext *getParent() {
  1928.     return cast<Decl>(this)->getDeclContext();
  1929.   }
  1930.   const DeclContext *getParent() const {
  1931.     return const_cast<DeclContext*>(this)->getParent();
  1932.   }
  1933.  
  1934.   /// getLexicalParent - Returns the containing lexical DeclContext. May be
  1935.   /// different from getParent, e.g.:
  1936.   ///
  1937.   ///   namespace A {
  1938.   ///      struct S;
  1939.   ///   }
  1940.   ///   struct A::S {}; // getParent() == namespace 'A'
  1941.   ///                   // getLexicalParent() == translation unit
  1942.   ///
  1943.   DeclContext *getLexicalParent() {
  1944.     return cast<Decl>(this)->getLexicalDeclContext();
  1945.   }
  1946.   const DeclContext *getLexicalParent() const {
  1947.     return const_cast<DeclContext*>(this)->getLexicalParent();
  1948.   }
  1949.  
  1950.   DeclContext *getLookupParent();
  1951.  
  1952.   const DeclContext *getLookupParent() const {
  1953.     return const_cast<DeclContext*>(this)->getLookupParent();
  1954.   }
  1955.  
  1956.   ASTContext &getParentASTContext() const {
  1957.     return cast<Decl>(this)->getASTContext();
  1958.   }
  1959.  
  1960.   bool isClosure() const { return getDeclKind() == Decl::Block; }
  1961.  
  1962.   /// Return this DeclContext if it is a BlockDecl. Otherwise, return the
  1963.   /// innermost enclosing BlockDecl or null if there are no enclosing blocks.
  1964.   const BlockDecl *getInnermostBlockDecl() const;
  1965.  
  1966.   bool isObjCContainer() const {
  1967.     switch (getDeclKind()) {
  1968.     case Decl::ObjCCategory:
  1969.     case Decl::ObjCCategoryImpl:
  1970.     case Decl::ObjCImplementation:
  1971.     case Decl::ObjCInterface:
  1972.     case Decl::ObjCProtocol:
  1973.       return true;
  1974.     default:
  1975.       return false;
  1976.     }
  1977.   }
  1978.  
  1979.   bool isFunctionOrMethod() const {
  1980.     switch (getDeclKind()) {
  1981.     case Decl::Block:
  1982.     case Decl::Captured:
  1983.     case Decl::ObjCMethod:
  1984.       return true;
  1985.     default:
  1986.       return getDeclKind() >= Decl::firstFunction &&
  1987.              getDeclKind() <= Decl::lastFunction;
  1988.     }
  1989.   }
  1990.  
  1991.   /// Test whether the context supports looking up names.
  1992.   bool isLookupContext() const {
  1993.     return !isFunctionOrMethod() && getDeclKind() != Decl::LinkageSpec &&
  1994.            getDeclKind() != Decl::Export;
  1995.   }
  1996.  
  1997.   bool isFileContext() const {
  1998.     return getDeclKind() == Decl::TranslationUnit ||
  1999.            getDeclKind() == Decl::Namespace;
  2000.   }
  2001.  
  2002.   bool isTranslationUnit() const {
  2003.     return getDeclKind() == Decl::TranslationUnit;
  2004.   }
  2005.  
  2006.   bool isRecord() const {
  2007.     return getDeclKind() >= Decl::firstRecord &&
  2008.            getDeclKind() <= Decl::lastRecord;
  2009.   }
  2010.  
  2011.   bool isNamespace() const { return getDeclKind() == Decl::Namespace; }
  2012.  
  2013.   bool isStdNamespace() const;
  2014.  
  2015.   bool isInlineNamespace() const;
  2016.  
  2017.   /// Determines whether this context is dependent on a
  2018.   /// template parameter.
  2019.   bool isDependentContext() const;
  2020.  
  2021.   /// isTransparentContext - Determines whether this context is a
  2022.   /// "transparent" context, meaning that the members declared in this
  2023.   /// context are semantically declared in the nearest enclosing
  2024.   /// non-transparent (opaque) context but are lexically declared in
  2025.   /// this context. For example, consider the enumerators of an
  2026.   /// enumeration type:
  2027.   /// @code
  2028.   /// enum E {
  2029.   ///   Val1
  2030.   /// };
  2031.   /// @endcode
  2032.   /// Here, E is a transparent context, so its enumerator (Val1) will
  2033.   /// appear (semantically) that it is in the same context of E.
  2034.   /// Examples of transparent contexts include: enumerations (except for
  2035.   /// C++0x scoped enums), C++ linkage specifications and export declaration.
  2036.   bool isTransparentContext() const;
  2037.  
  2038.   /// Determines whether this context or some of its ancestors is a
  2039.   /// linkage specification context that specifies C linkage.
  2040.   bool isExternCContext() const;
  2041.  
  2042.   /// Retrieve the nearest enclosing C linkage specification context.
  2043.   const LinkageSpecDecl *getExternCContext() const;
  2044.  
  2045.   /// Determines whether this context or some of its ancestors is a
  2046.   /// linkage specification context that specifies C++ linkage.
  2047.   bool isExternCXXContext() const;
  2048.  
  2049.   /// Determine whether this declaration context is equivalent
  2050.   /// to the declaration context DC.
  2051.   bool Equals(const DeclContext *DC) const {
  2052.     return DC && this->getPrimaryContext() == DC->getPrimaryContext();
  2053.   }
  2054.  
  2055.   /// Determine whether this declaration context encloses the
  2056.   /// declaration context DC.
  2057.   bool Encloses(const DeclContext *DC) const;
  2058.  
  2059.   /// Find the nearest non-closure ancestor of this context,
  2060.   /// i.e. the innermost semantic parent of this context which is not
  2061.   /// a closure.  A context may be its own non-closure ancestor.
  2062.   Decl *getNonClosureAncestor();
  2063.   const Decl *getNonClosureAncestor() const {
  2064.     return const_cast<DeclContext*>(this)->getNonClosureAncestor();
  2065.   }
  2066.  
  2067.   // Retrieve the nearest context that is not a transparent context.
  2068.   DeclContext *getNonTransparentContext();
  2069.   const DeclContext *getNonTransparentContext() const {
  2070.     return const_cast<DeclContext *>(this)->getNonTransparentContext();
  2071.   }
  2072.  
  2073.   /// getPrimaryContext - There may be many different
  2074.   /// declarations of the same entity (including forward declarations
  2075.   /// of classes, multiple definitions of namespaces, etc.), each with
  2076.   /// a different set of declarations. This routine returns the
  2077.   /// "primary" DeclContext structure, which will contain the
  2078.   /// information needed to perform name lookup into this context.
  2079.   DeclContext *getPrimaryContext();
  2080.   const DeclContext *getPrimaryContext() const {
  2081.     return const_cast<DeclContext*>(this)->getPrimaryContext();
  2082.   }
  2083.  
  2084.   /// getRedeclContext - Retrieve the context in which an entity conflicts with
  2085.   /// other entities of the same name, or where it is a redeclaration if the
  2086.   /// two entities are compatible. This skips through transparent contexts.
  2087.   DeclContext *getRedeclContext();
  2088.   const DeclContext *getRedeclContext() const {
  2089.     return const_cast<DeclContext *>(this)->getRedeclContext();
  2090.   }
  2091.  
  2092.   /// Retrieve the nearest enclosing namespace context.
  2093.   DeclContext *getEnclosingNamespaceContext();
  2094.   const DeclContext *getEnclosingNamespaceContext() const {
  2095.     return const_cast<DeclContext *>(this)->getEnclosingNamespaceContext();
  2096.   }
  2097.  
  2098.   /// Retrieve the outermost lexically enclosing record context.
  2099.   RecordDecl *getOuterLexicalRecordContext();
  2100.   const RecordDecl *getOuterLexicalRecordContext() const {
  2101.     return const_cast<DeclContext *>(this)->getOuterLexicalRecordContext();
  2102.   }
  2103.  
  2104.   /// Test if this context is part of the enclosing namespace set of
  2105.   /// the context NS, as defined in C++0x [namespace.def]p9. If either context
  2106.   /// isn't a namespace, this is equivalent to Equals().
  2107.   ///
  2108.   /// The enclosing namespace set of a namespace is the namespace and, if it is
  2109.   /// inline, its enclosing namespace, recursively.
  2110.   bool InEnclosingNamespaceSetOf(const DeclContext *NS) const;
  2111.  
  2112.   /// Collects all of the declaration contexts that are semantically
  2113.   /// connected to this declaration context.
  2114.   ///
  2115.   /// For declaration contexts that have multiple semantically connected but
  2116.   /// syntactically distinct contexts, such as C++ namespaces, this routine
  2117.   /// retrieves the complete set of such declaration contexts in source order.
  2118.   /// For example, given:
  2119.   ///
  2120.   /// \code
  2121.   /// namespace N {
  2122.   ///   int x;
  2123.   /// }
  2124.   /// namespace N {
  2125.   ///   int y;
  2126.   /// }
  2127.   /// \endcode
  2128.   ///
  2129.   /// The \c Contexts parameter will contain both definitions of N.
  2130.   ///
  2131.   /// \param Contexts Will be cleared and set to the set of declaration
  2132.   /// contexts that are semanticaly connected to this declaration context,
  2133.   /// in source order, including this context (which may be the only result,
  2134.   /// for non-namespace contexts).
  2135.   void collectAllContexts(SmallVectorImpl<DeclContext *> &Contexts);
  2136.  
  2137.   /// decl_iterator - Iterates through the declarations stored
  2138.   /// within this context.
  2139.   class decl_iterator {
  2140.     /// Current - The current declaration.
  2141.     Decl *Current = nullptr;
  2142.  
  2143.   public:
  2144.     using value_type = Decl *;
  2145.     using reference = const value_type &;
  2146.     using pointer = const value_type *;
  2147.     using iterator_category = std::forward_iterator_tag;
  2148.     using difference_type = std::ptrdiff_t;
  2149.  
  2150.     decl_iterator() = default;
  2151.     explicit decl_iterator(Decl *C) : Current(C) {}
  2152.  
  2153.     reference operator*() const { return Current; }
  2154.  
  2155.     // This doesn't meet the iterator requirements, but it's convenient
  2156.     value_type operator->() const { return Current; }
  2157.  
  2158.     decl_iterator& operator++() {
  2159.       Current = Current->getNextDeclInContext();
  2160.       return *this;
  2161.     }
  2162.  
  2163.     decl_iterator operator++(int) {
  2164.       decl_iterator tmp(*this);
  2165.       ++(*this);
  2166.       return tmp;
  2167.     }
  2168.  
  2169.     friend bool operator==(decl_iterator x, decl_iterator y) {
  2170.       return x.Current == y.Current;
  2171.     }
  2172.  
  2173.     friend bool operator!=(decl_iterator x, decl_iterator y) {
  2174.       return x.Current != y.Current;
  2175.     }
  2176.   };
  2177.  
  2178.   using decl_range = llvm::iterator_range<decl_iterator>;
  2179.  
  2180.   /// decls_begin/decls_end - Iterate over the declarations stored in
  2181.   /// this context.
  2182.   decl_range decls() const { return decl_range(decls_begin(), decls_end()); }
  2183.   decl_iterator decls_begin() const;
  2184.   decl_iterator decls_end() const { return decl_iterator(); }
  2185.   bool decls_empty() const;
  2186.  
  2187.   /// noload_decls_begin/end - Iterate over the declarations stored in this
  2188.   /// context that are currently loaded; don't attempt to retrieve anything
  2189.   /// from an external source.
  2190.   decl_range noload_decls() const {
  2191.     return decl_range(noload_decls_begin(), noload_decls_end());
  2192.   }
  2193.   decl_iterator noload_decls_begin() const { return decl_iterator(FirstDecl); }
  2194.   decl_iterator noload_decls_end() const { return decl_iterator(); }
  2195.  
  2196.   /// specific_decl_iterator - Iterates over a subrange of
  2197.   /// declarations stored in a DeclContext, providing only those that
  2198.   /// are of type SpecificDecl (or a class derived from it). This
  2199.   /// iterator is used, for example, to provide iteration over just
  2200.   /// the fields within a RecordDecl (with SpecificDecl = FieldDecl).
  2201.   template<typename SpecificDecl>
  2202.   class specific_decl_iterator {
  2203.     /// Current - The current, underlying declaration iterator, which
  2204.     /// will either be NULL or will point to a declaration of
  2205.     /// type SpecificDecl.
  2206.     DeclContext::decl_iterator Current;
  2207.  
  2208.     /// SkipToNextDecl - Advances the current position up to the next
  2209.     /// declaration of type SpecificDecl that also meets the criteria
  2210.     /// required by Acceptable.
  2211.     void SkipToNextDecl() {
  2212.       while (*Current && !isa<SpecificDecl>(*Current))
  2213.         ++Current;
  2214.     }
  2215.  
  2216.   public:
  2217.     using value_type = SpecificDecl *;
  2218.     // TODO: Add reference and pointer types (with some appropriate proxy type)
  2219.     // if we ever have a need for them.
  2220.     using reference = void;
  2221.     using pointer = void;
  2222.     using difference_type =
  2223.         std::iterator_traits<DeclContext::decl_iterator>::difference_type;
  2224.     using iterator_category = std::forward_iterator_tag;
  2225.  
  2226.     specific_decl_iterator() = default;
  2227.  
  2228.     /// specific_decl_iterator - Construct a new iterator over a
  2229.     /// subset of the declarations the range [C,
  2230.     /// end-of-declarations). If A is non-NULL, it is a pointer to a
  2231.     /// member function of SpecificDecl that should return true for
  2232.     /// all of the SpecificDecl instances that will be in the subset
  2233.     /// of iterators. For example, if you want Objective-C instance
  2234.     /// methods, SpecificDecl will be ObjCMethodDecl and A will be
  2235.     /// &ObjCMethodDecl::isInstanceMethod.
  2236.     explicit specific_decl_iterator(DeclContext::decl_iterator C) : Current(C) {
  2237.       SkipToNextDecl();
  2238.     }
  2239.  
  2240.     value_type operator*() const { return cast<SpecificDecl>(*Current); }
  2241.  
  2242.     // This doesn't meet the iterator requirements, but it's convenient
  2243.     value_type operator->() const { return **this; }
  2244.  
  2245.     specific_decl_iterator& operator++() {
  2246.       ++Current;
  2247.       SkipToNextDecl();
  2248.       return *this;
  2249.     }
  2250.  
  2251.     specific_decl_iterator operator++(int) {
  2252.       specific_decl_iterator tmp(*this);
  2253.       ++(*this);
  2254.       return tmp;
  2255.     }
  2256.  
  2257.     friend bool operator==(const specific_decl_iterator& x,
  2258.                            const specific_decl_iterator& y) {
  2259.       return x.Current == y.Current;
  2260.     }
  2261.  
  2262.     friend bool operator!=(const specific_decl_iterator& x,
  2263.                            const specific_decl_iterator& y) {
  2264.       return x.Current != y.Current;
  2265.     }
  2266.   };
  2267.  
  2268.   /// Iterates over a filtered subrange of declarations stored
  2269.   /// in a DeclContext.
  2270.   ///
  2271.   /// This iterator visits only those declarations that are of type
  2272.   /// SpecificDecl (or a class derived from it) and that meet some
  2273.   /// additional run-time criteria. This iterator is used, for
  2274.   /// example, to provide access to the instance methods within an
  2275.   /// Objective-C interface (with SpecificDecl = ObjCMethodDecl and
  2276.   /// Acceptable = ObjCMethodDecl::isInstanceMethod).
  2277.   template<typename SpecificDecl, bool (SpecificDecl::*Acceptable)() const>
  2278.   class filtered_decl_iterator {
  2279.     /// Current - The current, underlying declaration iterator, which
  2280.     /// will either be NULL or will point to a declaration of
  2281.     /// type SpecificDecl.
  2282.     DeclContext::decl_iterator Current;
  2283.  
  2284.     /// SkipToNextDecl - Advances the current position up to the next
  2285.     /// declaration of type SpecificDecl that also meets the criteria
  2286.     /// required by Acceptable.
  2287.     void SkipToNextDecl() {
  2288.       while (*Current &&
  2289.              (!isa<SpecificDecl>(*Current) ||
  2290.               (Acceptable && !(cast<SpecificDecl>(*Current)->*Acceptable)())))
  2291.         ++Current;
  2292.     }
  2293.  
  2294.   public:
  2295.     using value_type = SpecificDecl *;
  2296.     // TODO: Add reference and pointer types (with some appropriate proxy type)
  2297.     // if we ever have a need for them.
  2298.     using reference = void;
  2299.     using pointer = void;
  2300.     using difference_type =
  2301.         std::iterator_traits<DeclContext::decl_iterator>::difference_type;
  2302.     using iterator_category = std::forward_iterator_tag;
  2303.  
  2304.     filtered_decl_iterator() = default;
  2305.  
  2306.     /// filtered_decl_iterator - Construct a new iterator over a
  2307.     /// subset of the declarations the range [C,
  2308.     /// end-of-declarations). If A is non-NULL, it is a pointer to a
  2309.     /// member function of SpecificDecl that should return true for
  2310.     /// all of the SpecificDecl instances that will be in the subset
  2311.     /// of iterators. For example, if you want Objective-C instance
  2312.     /// methods, SpecificDecl will be ObjCMethodDecl and A will be
  2313.     /// &ObjCMethodDecl::isInstanceMethod.
  2314.     explicit filtered_decl_iterator(DeclContext::decl_iterator C) : Current(C) {
  2315.       SkipToNextDecl();
  2316.     }
  2317.  
  2318.     value_type operator*() const { return cast<SpecificDecl>(*Current); }
  2319.     value_type operator->() const { return cast<SpecificDecl>(*Current); }
  2320.  
  2321.     filtered_decl_iterator& operator++() {
  2322.       ++Current;
  2323.       SkipToNextDecl();
  2324.       return *this;
  2325.     }
  2326.  
  2327.     filtered_decl_iterator operator++(int) {
  2328.       filtered_decl_iterator tmp(*this);
  2329.       ++(*this);
  2330.       return tmp;
  2331.     }
  2332.  
  2333.     friend bool operator==(const filtered_decl_iterator& x,
  2334.                            const filtered_decl_iterator& y) {
  2335.       return x.Current == y.Current;
  2336.     }
  2337.  
  2338.     friend bool operator!=(const filtered_decl_iterator& x,
  2339.                            const filtered_decl_iterator& y) {
  2340.       return x.Current != y.Current;
  2341.     }
  2342.   };
  2343.  
  2344.   /// Add the declaration D into this context.
  2345.   ///
  2346.   /// This routine should be invoked when the declaration D has first
  2347.   /// been declared, to place D into the context where it was
  2348.   /// (lexically) defined. Every declaration must be added to one
  2349.   /// (and only one!) context, where it can be visited via
  2350.   /// [decls_begin(), decls_end()). Once a declaration has been added
  2351.   /// to its lexical context, the corresponding DeclContext owns the
  2352.   /// declaration.
  2353.   ///
  2354.   /// If D is also a NamedDecl, it will be made visible within its
  2355.   /// semantic context via makeDeclVisibleInContext.
  2356.   void addDecl(Decl *D);
  2357.  
  2358.   /// Add the declaration D into this context, but suppress
  2359.   /// searches for external declarations with the same name.
  2360.   ///
  2361.   /// Although analogous in function to addDecl, this removes an
  2362.   /// important check.  This is only useful if the Decl is being
  2363.   /// added in response to an external search; in all other cases,
  2364.   /// addDecl() is the right function to use.
  2365.   /// See the ASTImporter for use cases.
  2366.   void addDeclInternal(Decl *D);
  2367.  
  2368.   /// Add the declaration D to this context without modifying
  2369.   /// any lookup tables.
  2370.   ///
  2371.   /// This is useful for some operations in dependent contexts where
  2372.   /// the semantic context might not be dependent;  this basically
  2373.   /// only happens with friends.
  2374.   void addHiddenDecl(Decl *D);
  2375.  
  2376.   /// Removes a declaration from this context.
  2377.   void removeDecl(Decl *D);
  2378.  
  2379.   /// Checks whether a declaration is in this context.
  2380.   bool containsDecl(Decl *D) const;
  2381.  
  2382.   /// Checks whether a declaration is in this context.
  2383.   /// This also loads the Decls from the external source before the check.
  2384.   bool containsDeclAndLoad(Decl *D) const;
  2385.  
  2386.   using lookup_result = DeclContextLookupResult;
  2387.   using lookup_iterator = lookup_result::iterator;
  2388.  
  2389.   /// lookup - Find the declarations (if any) with the given Name in
  2390.   /// this context. Returns a range of iterators that contains all of
  2391.   /// the declarations with this name, with object, function, member,
  2392.   /// and enumerator names preceding any tag name. Note that this
  2393.   /// routine will not look into parent contexts.
  2394.   lookup_result lookup(DeclarationName Name) const;
  2395.  
  2396.   /// Find the declarations with the given name that are visible
  2397.   /// within this context; don't attempt to retrieve anything from an
  2398.   /// external source.
  2399.   lookup_result noload_lookup(DeclarationName Name);
  2400.  
  2401.   /// A simplistic name lookup mechanism that performs name lookup
  2402.   /// into this declaration context without consulting the external source.
  2403.   ///
  2404.   /// This function should almost never be used, because it subverts the
  2405.   /// usual relationship between a DeclContext and the external source.
  2406.   /// See the ASTImporter for the (few, but important) use cases.
  2407.   ///
  2408.   /// FIXME: This is very inefficient; replace uses of it with uses of
  2409.   /// noload_lookup.
  2410.   void localUncachedLookup(DeclarationName Name,
  2411.                            SmallVectorImpl<NamedDecl *> &Results);
  2412.  
  2413.   /// Makes a declaration visible within this context.
  2414.   ///
  2415.   /// This routine makes the declaration D visible to name lookup
  2416.   /// within this context and, if this is a transparent context,
  2417.   /// within its parent contexts up to the first enclosing
  2418.   /// non-transparent context. Making a declaration visible within a
  2419.   /// context does not transfer ownership of a declaration, and a
  2420.   /// declaration can be visible in many contexts that aren't its
  2421.   /// lexical context.
  2422.   ///
  2423.   /// If D is a redeclaration of an existing declaration that is
  2424.   /// visible from this context, as determined by
  2425.   /// NamedDecl::declarationReplaces, the previous declaration will be
  2426.   /// replaced with D.
  2427.   void makeDeclVisibleInContext(NamedDecl *D);
  2428.  
  2429.   /// all_lookups_iterator - An iterator that provides a view over the results
  2430.   /// of looking up every possible name.
  2431.   class all_lookups_iterator;
  2432.  
  2433.   using lookups_range = llvm::iterator_range<all_lookups_iterator>;
  2434.  
  2435.   lookups_range lookups() const;
  2436.   // Like lookups(), but avoids loading external declarations.
  2437.   // If PreserveInternalState, avoids building lookup data structures too.
  2438.   lookups_range noload_lookups(bool PreserveInternalState) const;
  2439.  
  2440.   /// Iterators over all possible lookups within this context.
  2441.   all_lookups_iterator lookups_begin() const;
  2442.   all_lookups_iterator lookups_end() const;
  2443.  
  2444.   /// Iterators over all possible lookups within this context that are
  2445.   /// currently loaded; don't attempt to retrieve anything from an external
  2446.   /// source.
  2447.   all_lookups_iterator noload_lookups_begin() const;
  2448.   all_lookups_iterator noload_lookups_end() const;
  2449.  
  2450.   struct udir_iterator;
  2451.  
  2452.   using udir_iterator_base =
  2453.       llvm::iterator_adaptor_base<udir_iterator, lookup_iterator,
  2454.                                   typename lookup_iterator::iterator_category,
  2455.                                   UsingDirectiveDecl *>;
  2456.  
  2457.   struct udir_iterator : udir_iterator_base {
  2458.     udir_iterator(lookup_iterator I) : udir_iterator_base(I) {}
  2459.  
  2460.     UsingDirectiveDecl *operator*() const;
  2461.   };
  2462.  
  2463.   using udir_range = llvm::iterator_range<udir_iterator>;
  2464.  
  2465.   udir_range using_directives() const;
  2466.  
  2467.   // These are all defined in DependentDiagnostic.h.
  2468.   class ddiag_iterator;
  2469.  
  2470.   using ddiag_range = llvm::iterator_range<DeclContext::ddiag_iterator>;
  2471.  
  2472.   inline ddiag_range ddiags() const;
  2473.  
  2474.   // Low-level accessors
  2475.  
  2476.   /// Mark that there are external lexical declarations that we need
  2477.   /// to include in our lookup table (and that are not available as external
  2478.   /// visible lookups). These extra lookup results will be found by walking
  2479.   /// the lexical declarations of this context. This should be used only if
  2480.   /// setHasExternalLexicalStorage() has been called on any decl context for
  2481.   /// which this is the primary context.
  2482.   void setMustBuildLookupTable() {
  2483.     assert(this == getPrimaryContext() &&
  2484.            "should only be called on primary context");
  2485.     DeclContextBits.HasLazyExternalLexicalLookups = true;
  2486.   }
  2487.  
  2488.   /// Retrieve the internal representation of the lookup structure.
  2489.   /// This may omit some names if we are lazily building the structure.
  2490.   StoredDeclsMap *getLookupPtr() const { return LookupPtr; }
  2491.  
  2492.   /// Ensure the lookup structure is fully-built and return it.
  2493.   StoredDeclsMap *buildLookup();
  2494.  
  2495.   /// Whether this DeclContext has external storage containing
  2496.   /// additional declarations that are lexically in this context.
  2497.   bool hasExternalLexicalStorage() const {
  2498.     return DeclContextBits.ExternalLexicalStorage;
  2499.   }
  2500.  
  2501.   /// State whether this DeclContext has external storage for
  2502.   /// declarations lexically in this context.
  2503.   void setHasExternalLexicalStorage(bool ES = true) const {
  2504.     DeclContextBits.ExternalLexicalStorage = ES;
  2505.   }
  2506.  
  2507.   /// Whether this DeclContext has external storage containing
  2508.   /// additional declarations that are visible in this context.
  2509.   bool hasExternalVisibleStorage() const {
  2510.     return DeclContextBits.ExternalVisibleStorage;
  2511.   }
  2512.  
  2513.   /// State whether this DeclContext has external storage for
  2514.   /// declarations visible in this context.
  2515.   void setHasExternalVisibleStorage(bool ES = true) const {
  2516.     DeclContextBits.ExternalVisibleStorage = ES;
  2517.     if (ES && LookupPtr)
  2518.       DeclContextBits.NeedToReconcileExternalVisibleStorage = true;
  2519.   }
  2520.  
  2521.   /// Determine whether the given declaration is stored in the list of
  2522.   /// declarations lexically within this context.
  2523.   bool isDeclInLexicalTraversal(const Decl *D) const {
  2524.     return D && (D->NextInContextAndBits.getPointer() || D == FirstDecl ||
  2525.                  D == LastDecl);
  2526.   }
  2527.  
  2528.   bool setUseQualifiedLookup(bool use = true) const {
  2529.     bool old_value = DeclContextBits.UseQualifiedLookup;
  2530.     DeclContextBits.UseQualifiedLookup = use;
  2531.     return old_value;
  2532.   }
  2533.  
  2534.   bool shouldUseQualifiedLookup() const {
  2535.     return DeclContextBits.UseQualifiedLookup;
  2536.   }
  2537.  
  2538.   static bool classof(const Decl *D);
  2539.   static bool classof(const DeclContext *D) { return true; }
  2540.  
  2541.   void dumpAsDecl() const;
  2542.   void dumpAsDecl(const ASTContext *Ctx) const;
  2543.   void dumpDeclContext() const;
  2544.   void dumpLookups() const;
  2545.   void dumpLookups(llvm::raw_ostream &OS, bool DumpDecls = false,
  2546.                    bool Deserialize = false) const;
  2547.  
  2548. private:
  2549.   /// Whether this declaration context has had externally visible
  2550.   /// storage added since the last lookup. In this case, \c LookupPtr's
  2551.   /// invariant may not hold and needs to be fixed before we perform
  2552.   /// another lookup.
  2553.   bool hasNeedToReconcileExternalVisibleStorage() const {
  2554.     return DeclContextBits.NeedToReconcileExternalVisibleStorage;
  2555.   }
  2556.  
  2557.   /// State that this declaration context has had externally visible
  2558.   /// storage added since the last lookup. In this case, \c LookupPtr's
  2559.   /// invariant may not hold and needs to be fixed before we perform
  2560.   /// another lookup.
  2561.   void setNeedToReconcileExternalVisibleStorage(bool Need = true) const {
  2562.     DeclContextBits.NeedToReconcileExternalVisibleStorage = Need;
  2563.   }
  2564.  
  2565.   /// If \c true, this context may have local lexical declarations
  2566.   /// that are missing from the lookup table.
  2567.   bool hasLazyLocalLexicalLookups() const {
  2568.     return DeclContextBits.HasLazyLocalLexicalLookups;
  2569.   }
  2570.  
  2571.   /// If \c true, this context may have local lexical declarations
  2572.   /// that are missing from the lookup table.
  2573.   void setHasLazyLocalLexicalLookups(bool HasLLLL = true) const {
  2574.     DeclContextBits.HasLazyLocalLexicalLookups = HasLLLL;
  2575.   }
  2576.  
  2577.   /// If \c true, the external source may have lexical declarations
  2578.   /// that are missing from the lookup table.
  2579.   bool hasLazyExternalLexicalLookups() const {
  2580.     return DeclContextBits.HasLazyExternalLexicalLookups;
  2581.   }
  2582.  
  2583.   /// If \c true, the external source may have lexical declarations
  2584.   /// that are missing from the lookup table.
  2585.   void setHasLazyExternalLexicalLookups(bool HasLELL = true) const {
  2586.     DeclContextBits.HasLazyExternalLexicalLookups = HasLELL;
  2587.   }
  2588.  
  2589.   void reconcileExternalVisibleStorage() const;
  2590.   bool LoadLexicalDeclsFromExternalStorage() const;
  2591.  
  2592.   /// Makes a declaration visible within this context, but
  2593.   /// suppresses searches for external declarations with the same
  2594.   /// name.
  2595.   ///
  2596.   /// Analogous to makeDeclVisibleInContext, but for the exclusive
  2597.   /// use of addDeclInternal().
  2598.   void makeDeclVisibleInContextInternal(NamedDecl *D);
  2599.  
  2600.   StoredDeclsMap *CreateStoredDeclsMap(ASTContext &C) const;
  2601.  
  2602.   void loadLazyLocalLexicalLookups();
  2603.   void buildLookupImpl(DeclContext *DCtx, bool Internal);
  2604.   void makeDeclVisibleInContextWithFlags(NamedDecl *D, bool Internal,
  2605.                                          bool Rediscoverable);
  2606.   void makeDeclVisibleInContextImpl(NamedDecl *D, bool Internal);
  2607. };
  2608.  
  2609. inline bool Decl::isTemplateParameter() const {
  2610.   return getKind() == TemplateTypeParm || getKind() == NonTypeTemplateParm ||
  2611.          getKind() == TemplateTemplateParm;
  2612. }
  2613.  
  2614. // Specialization selected when ToTy is not a known subclass of DeclContext.
  2615. template <class ToTy,
  2616.           bool IsKnownSubtype = ::std::is_base_of<DeclContext, ToTy>::value>
  2617. struct cast_convert_decl_context {
  2618.   static const ToTy *doit(const DeclContext *Val) {
  2619.     return static_cast<const ToTy*>(Decl::castFromDeclContext(Val));
  2620.   }
  2621.  
  2622.   static ToTy *doit(DeclContext *Val) {
  2623.     return static_cast<ToTy*>(Decl::castFromDeclContext(Val));
  2624.   }
  2625. };
  2626.  
  2627. // Specialization selected when ToTy is a known subclass of DeclContext.
  2628. template <class ToTy>
  2629. struct cast_convert_decl_context<ToTy, true> {
  2630.   static const ToTy *doit(const DeclContext *Val) {
  2631.     return static_cast<const ToTy*>(Val);
  2632.   }
  2633.  
  2634.   static ToTy *doit(DeclContext *Val) {
  2635.     return static_cast<ToTy*>(Val);
  2636.   }
  2637. };
  2638.  
  2639. } // namespace clang
  2640.  
  2641. namespace llvm {
  2642.  
  2643. /// isa<T>(DeclContext*)
  2644. template <typename To>
  2645. struct isa_impl<To, ::clang::DeclContext> {
  2646.   static bool doit(const ::clang::DeclContext &Val) {
  2647.     return To::classofKind(Val.getDeclKind());
  2648.   }
  2649. };
  2650.  
  2651. /// cast<T>(DeclContext*)
  2652. template<class ToTy>
  2653. struct cast_convert_val<ToTy,
  2654.                         const ::clang::DeclContext,const ::clang::DeclContext> {
  2655.   static const ToTy &doit(const ::clang::DeclContext &Val) {
  2656.     return *::clang::cast_convert_decl_context<ToTy>::doit(&Val);
  2657.   }
  2658. };
  2659.  
  2660. template<class ToTy>
  2661. struct cast_convert_val<ToTy, ::clang::DeclContext, ::clang::DeclContext> {
  2662.   static ToTy &doit(::clang::DeclContext &Val) {
  2663.     return *::clang::cast_convert_decl_context<ToTy>::doit(&Val);
  2664.   }
  2665. };
  2666.  
  2667. template<class ToTy>
  2668. struct cast_convert_val<ToTy,
  2669.                      const ::clang::DeclContext*, const ::clang::DeclContext*> {
  2670.   static const ToTy *doit(const ::clang::DeclContext *Val) {
  2671.     return ::clang::cast_convert_decl_context<ToTy>::doit(Val);
  2672.   }
  2673. };
  2674.  
  2675. template<class ToTy>
  2676. struct cast_convert_val<ToTy, ::clang::DeclContext*, ::clang::DeclContext*> {
  2677.   static ToTy *doit(::clang::DeclContext *Val) {
  2678.     return ::clang::cast_convert_decl_context<ToTy>::doit(Val);
  2679.   }
  2680. };
  2681.  
  2682. /// Implement cast_convert_val for Decl -> DeclContext conversions.
  2683. template<class FromTy>
  2684. struct cast_convert_val< ::clang::DeclContext, FromTy, FromTy> {
  2685.   static ::clang::DeclContext &doit(const FromTy &Val) {
  2686.     return *FromTy::castToDeclContext(&Val);
  2687.   }
  2688. };
  2689.  
  2690. template<class FromTy>
  2691. struct cast_convert_val< ::clang::DeclContext, FromTy*, FromTy*> {
  2692.   static ::clang::DeclContext *doit(const FromTy *Val) {
  2693.     return FromTy::castToDeclContext(Val);
  2694.   }
  2695. };
  2696.  
  2697. template<class FromTy>
  2698. struct cast_convert_val< const ::clang::DeclContext, FromTy, FromTy> {
  2699.   static const ::clang::DeclContext &doit(const FromTy &Val) {
  2700.     return *FromTy::castToDeclContext(&Val);
  2701.   }
  2702. };
  2703.  
  2704. template<class FromTy>
  2705. struct cast_convert_val< const ::clang::DeclContext, FromTy*, FromTy*> {
  2706.   static const ::clang::DeclContext *doit(const FromTy *Val) {
  2707.     return FromTy::castToDeclContext(Val);
  2708.   }
  2709. };
  2710.  
  2711. } // namespace llvm
  2712.  
  2713. #endif // LLVM_CLANG_AST_DECLBASE_H
  2714.