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      1 //===--- Record.h - struct and class metadata for the VM --------*- 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 // A record is part of a program to describe the layout and methods of a struct.
     10 //
     11 //===----------------------------------------------------------------------===//
     12 
     13 #ifndef LLVM_CLANG_AST_INTERP_RECORD_H
     14 #define LLVM_CLANG_AST_INTERP_RECORD_H
     15 
     16 #include "Pointer.h"
     17 
     18 namespace clang {
     19 namespace interp {
     20 class Program;
     21 
     22 /// Structure/Class descriptor.
     23 class Record {
     24 public:
     25   /// Describes a record field.
     26   struct Field {
     27     const FieldDecl *Decl;
     28     unsigned Offset;
     29     Descriptor *Desc;
     30   };
     31 
     32   /// Describes a base class.
     33   struct Base {
     34     const RecordDecl *Decl;
     35     unsigned Offset;
     36     Descriptor *Desc;
     37     Record *R;
     38   };
     39 
     40   /// Mapping from identifiers to field descriptors.
     41   using FieldList = llvm::SmallVector<Field, 8>;
     42   /// Mapping from identifiers to base classes.
     43   using BaseList = llvm::SmallVector<Base, 8>;
     44   /// List of virtual base classes.
     45   using VirtualBaseList = llvm::SmallVector<Base, 2>;
     46 
     47 public:
     48   /// Returns the underlying declaration.
     49   const RecordDecl *getDecl() const { return Decl; }
     50   /// Checks if the record is a union.
     51   bool isUnion() const { return getDecl()->isUnion(); }
     52   /// Returns the size of the record.
     53   unsigned getSize() const { return BaseSize; }
     54   /// Returns the full size of the record, including records.
     55   unsigned getFullSize() const { return BaseSize + VirtualSize; }
     56   /// Returns a field.
     57   const Field *getField(const FieldDecl *FD) const;
     58   /// Returns a base descriptor.
     59   const Base *getBase(const RecordDecl *FD) const;
     60   /// Returns a virtual base descriptor.
     61   const Base *getVirtualBase(const RecordDecl *RD) const;
     62 
     63   using const_field_iter = FieldList::const_iterator;
     64   llvm::iterator_range<const_field_iter> fields() const {
     65     return llvm::make_range(Fields.begin(), Fields.end());
     66   }
     67 
     68   unsigned getNumFields() { return Fields.size(); }
     69   Field *getField(unsigned I) { return &Fields[I]; }
     70 
     71   using const_base_iter = BaseList::const_iterator;
     72   llvm::iterator_range<const_base_iter> bases() const {
     73     return llvm::make_range(Bases.begin(), Bases.end());
     74   }
     75 
     76   unsigned getNumBases() { return Bases.size(); }
     77   Base *getBase(unsigned I) { return &Bases[I]; }
     78 
     79   using const_virtual_iter = VirtualBaseList::const_iterator;
     80   llvm::iterator_range<const_virtual_iter> virtual_bases() const {
     81     return llvm::make_range(VirtualBases.begin(), VirtualBases.end());
     82   }
     83 
     84   unsigned getNumVirtualBases() { return VirtualBases.size(); }
     85   Base *getVirtualBase(unsigned I) { return &VirtualBases[I]; }
     86 
     87 private:
     88   /// Constructor used by Program to create record descriptors.
     89   Record(const RecordDecl *, BaseList &&Bases, FieldList &&Fields,
     90          VirtualBaseList &&VirtualBases, unsigned VirtualSize,
     91          unsigned BaseSize);
     92 
     93 private:
     94   friend class Program;
     95 
     96   /// Original declaration.
     97   const RecordDecl *Decl;
     98   /// List of all base classes.
     99   BaseList Bases;
    100   /// List of all the fields in the record.
    101   FieldList Fields;
    102   /// List o fall virtual bases.
    103   VirtualBaseList VirtualBases;
    104 
    105   /// Mapping from declarations to bases.
    106   llvm::DenseMap<const RecordDecl *, Base *> BaseMap;
    107   /// Mapping from field identifiers to descriptors.
    108   llvm::DenseMap<const FieldDecl *, Field *> FieldMap;
    109   /// Mapping from declarations to virtual bases.
    110   llvm::DenseMap<const RecordDecl *, Base *> VirtualBaseMap;
    111   /// Mapping from
    112   /// Size of the structure.
    113   unsigned BaseSize;
    114   /// Size of all virtual bases.
    115   unsigned VirtualSize;
    116 };
    117 
    118 } // namespace interp
    119 } // namespace clang
    120 
    121 #endif
    122