xref: /llvm-project/clang/lib/AST/ByteCode/Record.h (revision 7aec6dc477f8148ed066d10dfc7a012a51b6599c)
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 "Descriptor.h"
17 #include "clang/AST/Decl.h"
18 #include "clang/AST/DeclCXX.h"
19 
20 namespace clang {
21 namespace interp {
22 class Program;
23 
24 /// Structure/Class descriptor.
25 class Record final {
26 public:
27   /// Describes a record field.
28   struct Field {
29     const FieldDecl *Decl;
30     unsigned Offset;
31     const Descriptor *Desc;
32     bool isBitField() const { return Decl->isBitField(); }
33     bool isUnnamedBitField() const { return Decl->isUnnamedBitField(); }
34   };
35 
36   /// Describes a base class.
37   struct Base {
38     const RecordDecl *Decl;
39     unsigned Offset;
40     const Descriptor *Desc;
41     const Record *R;
42   };
43 
44   /// Mapping from identifiers to field descriptors.
45   using FieldList = llvm::SmallVector<Field, 8>;
46   /// Mapping from identifiers to base classes.
47   using BaseList = llvm::SmallVector<Base, 8>;
48   /// List of virtual base classes.
49   using VirtualBaseList = llvm::SmallVector<Base, 2>;
50 
51 public:
52   /// Returns the underlying declaration.
53   const RecordDecl *getDecl() const { return Decl; }
54   /// Returns the name of the underlying declaration.
55   const std::string getName() const;
56   /// Checks if the record is a union.
57   bool isUnion() const { return IsUnion; }
58   /// Checks if the record is an anonymous union.
59   bool isAnonymousUnion() const { return IsAnonymousUnion; }
60   /// Returns the size of the record.
61   unsigned getSize() const { return BaseSize; }
62   /// Returns the full size of the record, including records.
63   unsigned getFullSize() const { return BaseSize + VirtualSize; }
64   /// Returns a field.
65   const Field *getField(const FieldDecl *FD) const;
66   /// Returns a base descriptor.
67   const Base *getBase(const RecordDecl *FD) const;
68   /// Returns a base descriptor.
69   const Base *getBase(QualType T) const;
70   /// Returns a virtual base descriptor.
71   const Base *getVirtualBase(const RecordDecl *RD) const;
72   /// Returns the destructor of the record, if any.
73   const CXXDestructorDecl *getDestructor() const {
74     if (const auto *CXXDecl = dyn_cast<CXXRecordDecl>(Decl))
75       return CXXDecl->getDestructor();
76     return nullptr;
77   }
78 
79   using const_field_iter = FieldList::const_iterator;
80   llvm::iterator_range<const_field_iter> fields() const {
81     return llvm::make_range(Fields.begin(), Fields.end());
82   }
83 
84   unsigned getNumFields() const { return Fields.size(); }
85   const Field *getField(unsigned I) const { return &Fields[I]; }
86 
87   using const_base_iter = BaseList::const_iterator;
88   llvm::iterator_range<const_base_iter> bases() const {
89     return llvm::make_range(Bases.begin(), Bases.end());
90   }
91 
92   unsigned getNumBases() const { return Bases.size(); }
93   const Base *getBase(unsigned I) const {
94     assert(I < getNumBases());
95     return &Bases[I];
96   }
97 
98   using const_virtual_iter = VirtualBaseList::const_iterator;
99   llvm::iterator_range<const_virtual_iter> virtual_bases() const {
100     return llvm::make_range(VirtualBases.begin(), VirtualBases.end());
101   }
102 
103   unsigned getNumVirtualBases() const { return VirtualBases.size(); }
104   const Base *getVirtualBase(unsigned I) const { return &VirtualBases[I]; }
105 
106   void dump(llvm::raw_ostream &OS, unsigned Indentation = 0,
107             unsigned Offset = 0) const;
108   void dump() const { dump(llvm::errs()); }
109 
110 private:
111   /// Constructor used by Program to create record descriptors.
112   Record(const RecordDecl *, BaseList &&Bases, FieldList &&Fields,
113          VirtualBaseList &&VirtualBases, unsigned VirtualSize,
114          unsigned BaseSize);
115 
116 private:
117   friend class Program;
118 
119   /// Original declaration.
120   const RecordDecl *Decl;
121   /// List of all base classes.
122   BaseList Bases;
123   /// List of all the fields in the record.
124   FieldList Fields;
125   /// List o fall virtual bases.
126   VirtualBaseList VirtualBases;
127 
128   /// Mapping from declarations to bases.
129   llvm::DenseMap<const RecordDecl *, const Base *> BaseMap;
130   /// Mapping from field identifiers to descriptors.
131   llvm::DenseMap<const FieldDecl *, const Field *> FieldMap;
132   /// Mapping from declarations to virtual bases.
133   llvm::DenseMap<const RecordDecl *, Base *> VirtualBaseMap;
134   /// Size of the structure.
135   unsigned BaseSize;
136   /// Size of all virtual bases.
137   unsigned VirtualSize;
138   /// If this record is a union.
139   bool IsUnion;
140   /// If this is an anonymous union.
141   bool IsAnonymousUnion;
142 };
143 
144 } // namespace interp
145 } // namespace clang
146 
147 #endif
148