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      1 //===--- Attr.h - Classes for representing attributes ----------*- C++ -*-===//
      2 //
      3 //                     The LLVM Compiler Infrastructure
      4 //
      5 // This file is distributed under the University of Illinois Open Source
      6 // License. See LICENSE.TXT for details.
      7 //
      8 //===----------------------------------------------------------------------===//
      9 //
     10 //  This file defines the Attr interface and subclasses.
     11 //
     12 //===----------------------------------------------------------------------===//
     13 
     14 #ifndef LLVM_CLANG_AST_ATTR_H
     15 #define LLVM_CLANG_AST_ATTR_H
     16 
     17 #include "clang/AST/AttrIterator.h"
     18 #include "clang/AST/Decl.h"
     19 #include "clang/AST/Expr.h"
     20 #include "clang/AST/Type.h"
     21 #include "clang/Basic/AttrKinds.h"
     22 #include "clang/Basic/LLVM.h"
     23 #include "clang/Basic/SourceLocation.h"
     24 #include "clang/Basic/VersionTuple.h"
     25 #include "llvm/ADT/SmallVector.h"
     26 #include "llvm/ADT/StringRef.h"
     27 #include "llvm/ADT/StringSwitch.h"
     28 #include "llvm/Support/ErrorHandling.h"
     29 #include "llvm/Support/raw_ostream.h"
     30 #include <algorithm>
     31 #include <cassert>
     32 
     33 namespace clang {
     34   class ASTContext;
     35   class IdentifierInfo;
     36   class ObjCInterfaceDecl;
     37   class Expr;
     38   class QualType;
     39   class FunctionDecl;
     40   class TypeSourceInfo;
     41 
     42 /// Attr - This represents one attribute.
     43 class Attr {
     44 private:
     45   SourceRange Range;
     46   unsigned AttrKind : 16;
     47 
     48 protected:
     49   /// An index into the spelling list of an
     50   /// attribute defined in Attr.td file.
     51   unsigned SpellingListIndex : 4;
     52   bool Inherited : 1;
     53   bool IsPackExpansion : 1;
     54   bool Implicit : 1;
     55   bool IsLateParsed : 1;
     56   bool DuplicatesAllowed : 1;
     57 
     58   void* operator new(size_t bytes) throw() {
     59     llvm_unreachable("Attrs cannot be allocated with regular 'new'.");
     60   }
     61   void operator delete(void* data) throw() {
     62     llvm_unreachable("Attrs cannot be released with regular 'delete'.");
     63   }
     64 
     65 public:
     66   // Forward so that the regular new and delete do not hide global ones.
     67   void* operator new(size_t Bytes, ASTContext &C,
     68                      size_t Alignment = 8) throw() {
     69     return ::operator new(Bytes, C, Alignment);
     70   }
     71   void operator delete(void *Ptr, ASTContext &C,
     72                        size_t Alignment) throw() {
     73     return ::operator delete(Ptr, C, Alignment);
     74   }
     75 
     76 protected:
     77   Attr(attr::Kind AK, SourceRange R, unsigned SpellingListIndex,
     78        bool IsLateParsed, bool DuplicatesAllowed)
     79     : Range(R), AttrKind(AK), SpellingListIndex(SpellingListIndex),
     80       Inherited(false), IsPackExpansion(false), Implicit(false),
     81       IsLateParsed(IsLateParsed), DuplicatesAllowed(DuplicatesAllowed) {}
     82 
     83 public:
     84 
     85   attr::Kind getKind() const {
     86     return static_cast<attr::Kind>(AttrKind);
     87   }
     88 
     89   unsigned getSpellingListIndex() const { return SpellingListIndex; }
     90   const char *getSpelling() const;
     91 
     92   SourceLocation getLocation() const { return Range.getBegin(); }
     93   SourceRange getRange() const { return Range; }
     94   void setRange(SourceRange R) { Range = R; }
     95 
     96   bool isInherited() const { return Inherited; }
     97 
     98   /// \brief Returns true if the attribute has been implicitly created instead
     99   /// of explicitly written by the user.
    100   bool isImplicit() const { return Implicit; }
    101   void setImplicit(bool I) { Implicit = I; }
    102 
    103   void setPackExpansion(bool PE) { IsPackExpansion = PE; }
    104   bool isPackExpansion() const { return IsPackExpansion; }
    105 
    106   // Clone this attribute.
    107   Attr *clone(ASTContext &C) const;
    108 
    109   bool isLateParsed() const { return IsLateParsed; }
    110 
    111   // Pretty print this attribute.
    112   void printPretty(raw_ostream &OS, const PrintingPolicy &Policy) const;
    113 
    114   /// \brief By default, attributes cannot be duplicated when being merged;
    115   /// however, an attribute can override this. Returns true if the attribute
    116   /// can be duplicated when merging.
    117   bool duplicatesAllowed() const { return DuplicatesAllowed; }
    118 };
    119 
    120 class InheritableAttr : public Attr {
    121 protected:
    122   InheritableAttr(attr::Kind AK, SourceRange R, unsigned SpellingListIndex,
    123                   bool IsLateParsed, bool DuplicatesAllowed)
    124       : Attr(AK, R, SpellingListIndex, IsLateParsed, DuplicatesAllowed) {}
    125 
    126 public:
    127   void setInherited(bool I) { Inherited = I; }
    128 
    129   // Implement isa/cast/dyncast/etc.
    130   static bool classof(const Attr *A) {
    131     return A->getKind() <= attr::LAST_INHERITABLE;
    132   }
    133 };
    134 
    135 class InheritableParamAttr : public InheritableAttr {
    136 protected:
    137   InheritableParamAttr(attr::Kind AK, SourceRange R, unsigned SpellingListIndex,
    138                        bool IsLateParsed, bool DuplicatesAllowed)
    139       : InheritableAttr(AK, R, SpellingListIndex, IsLateParsed,
    140                         DuplicatesAllowed) {}
    141 
    142 public:
    143   // Implement isa/cast/dyncast/etc.
    144   static bool classof(const Attr *A) {
    145     // Relies on relative order of enum emission with respect to MS inheritance
    146     // attrs.
    147     return A->getKind() <= attr::LAST_INHERITABLE_PARAM;
    148   }
    149 };
    150 
    151 #include "clang/AST/Attrs.inc"
    152 
    153 inline const DiagnosticBuilder &operator<<(const DiagnosticBuilder &DB,
    154                                            const Attr *At) {
    155   DB.AddTaggedVal(reinterpret_cast<intptr_t>(At),
    156                   DiagnosticsEngine::ak_attr);
    157   return DB;
    158 }
    159 
    160 inline const PartialDiagnostic &operator<<(const PartialDiagnostic &PD,
    161                                            const Attr *At) {
    162   PD.AddTaggedVal(reinterpret_cast<intptr_t>(At),
    163                   DiagnosticsEngine::ak_attr);
    164   return PD;
    165 }
    166 }  // end namespace clang
    167 
    168 #endif
    169