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 31 namespace llvm { 32 33 class Argument; 34 class BasicBlock; 35 class Function; 36 class GlobalAlias; 37 class GlobalIFunc; 38 class GlobalVariable; 39 class Instruction; 40 class Module; 41 class 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. 47 template <typename NodeTy> struct SymbolTableListParentType {}; 48 49 #define DEFINE_SYMBOL_TABLE_PARENT_TYPE(NODE, PARENT) \ 50 template <> struct SymbolTableListParentType<NODE> { using type = PARENT; }; 51 DEFINE_SYMBOL_TABLE_PARENT_TYPE(Instruction, BasicBlock) 52 DEFINE_SYMBOL_TABLE_PARENT_TYPE(BasicBlock, Function) 53 DEFINE_SYMBOL_TABLE_PARENT_TYPE(Argument, Function) 54 DEFINE_SYMBOL_TABLE_PARENT_TYPE(Function, Module) 55 DEFINE_SYMBOL_TABLE_PARENT_TYPE(GlobalVariable, Module) 56 DEFINE_SYMBOL_TABLE_PARENT_TYPE(GlobalAlias, Module) 57 DEFINE_SYMBOL_TABLE_PARENT_TYPE(GlobalIFunc, Module) 58 #undef DEFINE_SYMBOL_TABLE_PARENT_TYPE 59 60 template <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 // 65 template <typename ValueSubClass> 66 class 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 72 public: 73 SymbolTableListTraits() = default; 74 75 private: 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(size_t(&((ItemParentClass*)nullptr->*ItemParentClass:: 80 getSublistAccess(static_cast<ValueSubClass*>(nullptr))))); 81 ListTy *Anchor(static_cast<ListTy *>(this)); 82 return reinterpret_cast<ItemParentClass*>(reinterpret_cast<char*>(Anchor)- 83 Offset); 84 } 85 86 static ListTy &getList(ItemParentClass *Par) { 87 return Par->*(Par->getSublistAccess((ValueSubClass*)nullptr)); 88 } 89 90 static ValueSymbolTable *getSymTab(ItemParentClass *Par) { 91 return Par ? toPtr(Par->getValueSymbolTable()) : nullptr; 92 } 93 94 public: 95 void addNodeToList(ValueSubClass *V); 96 void removeNodeFromList(ValueSubClass *V); 97 void transferNodesFromList(SymbolTableListTraits &L2, iterator first, 98 iterator last); 99 // private: 100 template<typename TPtr> 101 void setSymTabObject(TPtr *, TPtr); 102 static ValueSymbolTable *toPtr(ValueSymbolTable *P) { return P; } 103 static ValueSymbolTable *toPtr(ValueSymbolTable &R) { return &R; } 104 }; 105 106 /// List that automatically updates parent links and symbol tables. 107 /// 108 /// When nodes are inserted into and removed from this list, the associated 109 /// symbol table will be automatically updated. Similarly, parent links get 110 /// updated automatically. 111 template <class T> 112 class SymbolTableList 113 : public iplist_impl<simple_ilist<T>, SymbolTableListTraits<T>> {}; 114 115 } // end namespace llvm 116 117 #endif // LLVM_IR_SYMBOLTABLELISTTRAITS_H 118