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, typename... Args> 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// OptionsT - Extra options to ilist nodes.
65//
66template <typename ValueSubClass, typename... Args>
67class SymbolTableListTraits : public ilist_alloc_traits<ValueSubClass> {
68 using ListTy = SymbolTableList<ValueSubClass, Args...>;
69 using iterator = typename simple_ilist<ValueSubClass, Args...>::iterator;
70 using ItemParentClass =
71 typename SymbolTableListParentType<ValueSubClass>::type;
72
73public:
74 SymbolTableListTraits() = default;
75
76private:
77 /// getListOwner - Return the object that owns this list. If this is a list
78 /// of instructions, it returns the BasicBlock that owns them.
79 ItemParentClass *getListOwner() {
80 size_t Offset = reinterpret_cast<size_t>(
81 &((ItemParentClass *)nullptr->*ItemParentClass::getSublistAccess(
82 static_cast<ValueSubClass *>(
83 nullptr))));
84 ListTy *Anchor = static_cast<ListTy *>(this);
85 return reinterpret_cast<ItemParentClass*>(reinterpret_cast<char*>(Anchor)-
86 Offset);
87 }
88
89 static ListTy &getList(ItemParentClass *Par) {
90 return Par->*(Par->getSublistAccess((ValueSubClass*)nullptr));
91 }
92
93 static ValueSymbolTable *getSymTab(ItemParentClass *Par) {
94 return Par ? toPtr(Par->getValueSymbolTable()) : nullptr;
95 }
96
97public:
98 void addNodeToList(ValueSubClass *V);
99 void removeNodeFromList(ValueSubClass *V);
100 void transferNodesFromList(SymbolTableListTraits &L2, iterator first,
101 iterator last);
102 // private:
103 template<typename TPtr>
104 void setSymTabObject(TPtr *, TPtr);
105 static ValueSymbolTable *toPtr(ValueSymbolTable *P) { return P; }
106 static ValueSymbolTable *toPtr(ValueSymbolTable &R) { return &R; }
107};
108
109/// List that automatically updates parent links and symbol tables.
110///
111/// When nodes are inserted into and removed from this list, the associated
112/// symbol table will be automatically updated. Similarly, parent links get
113/// updated automatically.
114template <class T, typename... Args>
115class SymbolTableList : public iplist_impl<simple_ilist<T, Args...>,
116 SymbolTableListTraits<T, Args...>> {
117};
118
119} // end namespace llvm
120
121#endif // LLVM_IR_SYMBOLTABLELISTTRAITS_H
122