1//===- llvm/SymbolTableListTraits.h - Traits for iplist ---------*- 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 a generic class that is used to implement the automatic
10// symbol table manipulation that occurs when you put (for example) a named
11// instruction into a basic block.
12//
13// The way that this is implemented is by using a special traits class with the
14// intrusive list that makes up the list of instructions in a basic block. When
15// a new element is added to the list of instructions, the traits class is
16// notified, allowing the symbol table to be updated.
17//
18// This generic class implements the traits class. It must be generic so that
19// it can work for all uses it, which include lists of instructions, basic
20// blocks, arguments, functions, global variables, etc...
21//
22//===----------------------------------------------------------------------===//
23
24#ifndef LLVM_IR_SYMBOLTABLELISTTRAITS_H
25#define LLVM_IR_SYMBOLTABLELISTTRAITS_H
26
27#include "llvm/ADT/ilist.h"
28#include "llvm/ADT/simple_ilist.h"
29#include <cstddef>
30
31namespace llvm {
32
33class Argument;
34class BasicBlock;
35class Function;
36class GlobalAlias;
37class GlobalIFunc;
38class GlobalVariable;
39class Instruction;
40class Module;
41class ValueSymbolTable;
42
43/// Template metafunction to get the parent type for a symbol table list.
44///
45/// Implementations create a typedef called \c type so that we only need a
46/// single template parameter for the list and traits.
47template <typename NodeTy> struct SymbolTableListParentType {};
48
49#define DEFINE_SYMBOL_TABLE_PARENT_TYPE(NODE, PARENT) \
50 template <> struct SymbolTableListParentType<NODE> { using type = PARENT; };
51DEFINE_SYMBOL_TABLE_PARENT_TYPE(Instruction, BasicBlock)
52DEFINE_SYMBOL_TABLE_PARENT_TYPE(BasicBlock, Function)
53DEFINE_SYMBOL_TABLE_PARENT_TYPE(Argument, Function)
54DEFINE_SYMBOL_TABLE_PARENT_TYPE(Function, Module)
55DEFINE_SYMBOL_TABLE_PARENT_TYPE(GlobalVariable, Module)
56DEFINE_SYMBOL_TABLE_PARENT_TYPE(GlobalAlias, Module)
57DEFINE_SYMBOL_TABLE_PARENT_TYPE(GlobalIFunc, Module)
58#undef DEFINE_SYMBOL_TABLE_PARENT_TYPE
59
60template <typename NodeTy> class SymbolTableList;
61
62// ValueSubClass - The type of objects that I hold, e.g. Instruction.
63// ItemParentClass - The type of object that owns the list, e.g. BasicBlock.
64//
65template <typename ValueSubClass>
66class SymbolTableListTraits : public ilist_alloc_traits<ValueSubClass> {
67 using ListTy = SymbolTableList<ValueSubClass>;
68 using iterator = typename simple_ilist<ValueSubClass>::iterator;
69 using ItemParentClass =
70 typename SymbolTableListParentType<ValueSubClass>::type;
71
72public:
73 SymbolTableListTraits() = default;
74
75private:
76 /// getListOwner - Return the object that owns this list. If this is a list
77 /// of instructions, it returns the BasicBlock that owns them.
78 ItemParentClass *getListOwner() {
79 size_t Offset = reinterpret_cast<size_t>(
80 &((ItemParentClass *)nullptr->*ItemParentClass::getSublistAccess(
81 static_cast<ValueSubClass *>(
82 nullptr))));
83 ListTy *Anchor = static_cast<ListTy *>(this);
84 return reinterpret_cast<ItemParentClass*>(reinterpret_cast<char*>(Anchor)-
85 Offset);
86 }
87
88 static ListTy &getList(ItemParentClass *Par) {
89 return Par->*(Par->getSublistAccess((ValueSubClass*)nullptr));
90 }
91
92 static ValueSymbolTable *getSymTab(ItemParentClass *Par) {
93 return Par ? toPtr(Par->getValueSymbolTable()) : nullptr;
94 }
95
96public:
97 void addNodeToList(ValueSubClass *V);
98 void removeNodeFromList(ValueSubClass *V);
99 void transferNodesFromList(SymbolTableListTraits &L2, iterator first,
100 iterator last);
101 // private:
102 template<typename TPtr>
103 void setSymTabObject(TPtr *, TPtr);
104 static ValueSymbolTable *toPtr(ValueSymbolTable *P) { return P; }
105 static ValueSymbolTable *toPtr(ValueSymbolTable &R) { return &R; }
106};
107
108/// List that automatically updates parent links and symbol tables.
109///
110/// When nodes are inserted into and removed from this list, the associated
111/// symbol table will be automatically updated. Similarly, parent links get
112/// updated automatically.
113template <class T>
114class SymbolTableList
115 : public iplist_impl<simple_ilist<T>, SymbolTableListTraits<T>> {};
116
117} // end namespace llvm
118
119#endif // LLVM_IR_SYMBOLTABLELISTTRAITS_H
120