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, 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 // 66 template <typename ValueSubClass, typename... Args> 67 class 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 73 public: 74 SymbolTableListTraits() = default; 75 76 private: 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 97 public: 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. 114 template <class T, typename... Args> 115 class 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