1 //===- UDTLayout.h - UDT layout info ----------------------------*- 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 #ifndef LLVM_DEBUGINFO_PDB_UDTLAYOUT_H
10 #define LLVM_DEBUGINFO_PDB_UDTLAYOUT_H
11 
12 #include "llvm/ADT/ArrayRef.h"
13 #include "llvm/ADT/BitVector.h"
14 #include "llvm/ADT/StringRef.h"
15 #include "llvm/DebugInfo/PDB/PDBSymbol.h"
16 #include "llvm/DebugInfo/PDB/PDBSymbolData.h"
17 #include "llvm/DebugInfo/PDB/PDBSymbolTypeBaseClass.h"
18 #include "llvm/DebugInfo/PDB/PDBSymbolTypeBuiltin.h"
19 #include "llvm/DebugInfo/PDB/PDBSymbolTypeUDT.h"
20 #include "llvm/DebugInfo/PDB/PDBSymbolTypeVTable.h"
21 #include "llvm/DebugInfo/PDB/PDBTypes.h"
22 #include <cstdint>
23 #include <memory>
24 #include <string>
25 #include <vector>
26 
27 namespace llvm {
28 namespace pdb {
29 
30 class BaseClassLayout;
31 class ClassLayout;
32 class UDTLayoutBase;
33 
34 class LayoutItemBase {
35 public:
36   LayoutItemBase(const UDTLayoutBase *Parent, const PDBSymbol *Symbol,
37                  const std::string &Name, uint32_t OffsetInParent,
38                  uint32_t Size, bool IsElided);
39   virtual ~LayoutItemBase() = default;
40 
41   uint32_t deepPaddingSize() const;
immediatePadding()42   virtual uint32_t immediatePadding() const { return 0; }
43   virtual uint32_t tailPadding() const;
44 
getParent()45   const UDTLayoutBase *getParent() const { return Parent; }
getName()46   StringRef getName() const { return Name; }
getOffsetInParent()47   uint32_t getOffsetInParent() const { return OffsetInParent; }
getSize()48   uint32_t getSize() const { return SizeOf; }
getLayoutSize()49   uint32_t getLayoutSize() const { return LayoutSize; }
getSymbol()50   const PDBSymbol *getSymbol() const { return Symbol; }
usedBytes()51   const BitVector &usedBytes() const { return UsedBytes; }
isElided()52   bool isElided() const { return IsElided; }
isVBPtr()53   virtual bool isVBPtr() const { return false; }
54 
containsOffset(uint32_t Off)55   uint32_t containsOffset(uint32_t Off) const {
56     uint32_t Begin = getOffsetInParent();
57     uint32_t End = Begin + getSize();
58     return (Off >= Begin && Off < End);
59   }
60 
61 protected:
62   const PDBSymbol *Symbol = nullptr;
63   const UDTLayoutBase *Parent = nullptr;
64   BitVector UsedBytes;
65   std::string Name;
66   uint32_t OffsetInParent = 0;
67   uint32_t SizeOf = 0;
68   uint32_t LayoutSize = 0;
69   bool IsElided = false;
70 };
71 
72 class VBPtrLayoutItem : public LayoutItemBase {
73 public:
74   VBPtrLayoutItem(const UDTLayoutBase &Parent,
75                   std::unique_ptr<PDBSymbolTypeBuiltin> Sym, uint32_t Offset,
76                   uint32_t Size);
77 
isVBPtr()78   bool isVBPtr() const override { return true; }
79 
80 private:
81   std::unique_ptr<PDBSymbolTypeBuiltin> Type;
82 };
83 
84 class DataMemberLayoutItem : public LayoutItemBase {
85 public:
86   DataMemberLayoutItem(const UDTLayoutBase &Parent,
87                        std::unique_ptr<PDBSymbolData> DataMember);
88 
89   const PDBSymbolData &getDataMember();
90   bool hasUDTLayout() const;
91   const ClassLayout &getUDTLayout() const;
92 
93 private:
94   std::unique_ptr<PDBSymbolData> DataMember;
95   std::unique_ptr<ClassLayout> UdtLayout;
96 };
97 
98 class VTableLayoutItem : public LayoutItemBase {
99 public:
100   VTableLayoutItem(const UDTLayoutBase &Parent,
101                    std::unique_ptr<PDBSymbolTypeVTable> VTable);
102 
getElementSize()103   uint32_t getElementSize() const { return ElementSize; }
104 
105 private:
106   uint32_t ElementSize = 0;
107   std::unique_ptr<PDBSymbolTypeVTable> VTable;
108 };
109 
110 class UDTLayoutBase : public LayoutItemBase {
111   template <typename T> using UniquePtrVector = std::vector<std::unique_ptr<T>>;
112 
113 public:
114   UDTLayoutBase(const UDTLayoutBase *Parent, const PDBSymbol &Sym,
115                 const std::string &Name, uint32_t OffsetInParent, uint32_t Size,
116                 bool IsElided);
117 
118   uint32_t tailPadding() const override;
layout_items()119   ArrayRef<LayoutItemBase *> layout_items() const { return LayoutItems; }
bases()120   ArrayRef<BaseClassLayout *> bases() const { return AllBases; }
regular_bases()121   ArrayRef<BaseClassLayout *> regular_bases() const { return NonVirtualBases; }
virtual_bases()122   ArrayRef<BaseClassLayout *> virtual_bases() const { return VirtualBases; }
directVirtualBaseCount()123   uint32_t directVirtualBaseCount() const { return DirectVBaseCount; }
funcs()124   ArrayRef<std::unique_ptr<PDBSymbolFunc>> funcs() const { return Funcs; }
other_items()125   ArrayRef<std::unique_ptr<PDBSymbol>> other_items() const { return Other; }
126 
127 protected:
128   bool hasVBPtrAtOffset(uint32_t Off) const;
129   void initializeChildren(const PDBSymbol &Sym);
130 
131   void addChildToLayout(std::unique_ptr<LayoutItemBase> Child);
132 
133   uint32_t DirectVBaseCount = 0;
134 
135   UniquePtrVector<PDBSymbol> Other;
136   UniquePtrVector<PDBSymbolFunc> Funcs;
137   UniquePtrVector<LayoutItemBase> ChildStorage;
138   std::vector<LayoutItemBase *> LayoutItems;
139 
140   std::vector<BaseClassLayout *> AllBases;
141   ArrayRef<BaseClassLayout *> NonVirtualBases;
142   ArrayRef<BaseClassLayout *> VirtualBases;
143 
144   VTableLayoutItem *VTable = nullptr;
145   VBPtrLayoutItem *VBPtr = nullptr;
146 };
147 
148 class BaseClassLayout : public UDTLayoutBase {
149 public:
150   BaseClassLayout(const UDTLayoutBase &Parent, uint32_t OffsetInParent,
151                   bool Elide, std::unique_ptr<PDBSymbolTypeBaseClass> Base);
152 
getBase()153   const PDBSymbolTypeBaseClass &getBase() const { return *Base; }
isVirtualBase()154   bool isVirtualBase() const { return IsVirtualBase; }
isEmptyBase()155   bool isEmptyBase() { return SizeOf == 1 && LayoutSize == 0; }
156 
157 private:
158   std::unique_ptr<PDBSymbolTypeBaseClass> Base;
159   bool IsVirtualBase;
160 };
161 
162 class ClassLayout : public UDTLayoutBase {
163 public:
164   explicit ClassLayout(const PDBSymbolTypeUDT &UDT);
165   explicit ClassLayout(std::unique_ptr<PDBSymbolTypeUDT> UDT);
166 
167   ClassLayout(ClassLayout &&Other) = default;
168 
getClass()169   const PDBSymbolTypeUDT &getClass() const { return UDT; }
170   uint32_t immediatePadding() const override;
171 
172 private:
173   BitVector ImmediateUsedBytes;
174   std::unique_ptr<PDBSymbolTypeUDT> OwnedStorage;
175   const PDBSymbolTypeUDT &UDT;
176 };
177 
178 } // end namespace pdb
179 } // end namespace llvm
180 
181 #endif // LLVM_DEBUGINFO_PDB_UDTLAYOUT_H
182