1 //===-- llvm/SymbolTableListTraits.h - Traits for iplist --------*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file defines a generic class that is used to implement the automatic
11 // symbol table manipulation that occurs when you put (for example) a named
12 // instruction into a basic block.
13 //
14 // The way that this is implemented is by using a special traits class with the
15 // intrusive list that makes up the list of instructions in a basic block.  When
16 // a new element is added to the list of instructions, the traits class is
17 // notified, allowing the symbol table to be updated.
18 //
19 // This generic class implements the traits class.  It must be generic so that
20 // it can work for all uses it, which include lists of instructions, basic
21 // blocks, arguments, functions, global variables, etc...
22 //
23 //===----------------------------------------------------------------------===//
24 
25 #ifndef LLVM_IR_SYMBOLTABLELISTTRAITS_H
26 #define LLVM_IR_SYMBOLTABLELISTTRAITS_H
27 
28 #include "llvm/ADT/ilist.h"
29 
30 namespace llvm {
31 class ValueSymbolTable;
32 
33 template<typename NodeTy> class ilist_iterator;
34 template<typename NodeTy, typename Traits> class iplist;
35 template<typename Ty> struct ilist_traits;
36 
37 // ValueSubClass   - The type of objects that I hold, e.g. Instruction.
38 // ItemParentClass - The type of object that owns the list, e.g. BasicBlock.
39 //
40 template<typename ValueSubClass, typename ItemParentClass>
41 class SymbolTableListTraits : public ilist_default_traits<ValueSubClass> {
42   typedef ilist_traits<ValueSubClass> TraitsClass;
43 public:
SymbolTableListTraits()44   SymbolTableListTraits() {}
45 
46   /// getListOwner - Return the object that owns this list.  If this is a list
47   /// of instructions, it returns the BasicBlock that owns them.
getListOwner()48   ItemParentClass *getListOwner() {
49     size_t Offset(size_t(&((ItemParentClass*)nullptr->*ItemParentClass::
50                            getSublistAccess(static_cast<ValueSubClass*>(nullptr)))));
51     iplist<ValueSubClass>* Anchor(static_cast<iplist<ValueSubClass>*>(this));
52     return reinterpret_cast<ItemParentClass*>(reinterpret_cast<char*>(Anchor)-
53                                               Offset);
54   }
55 
getList(ItemParentClass * Par)56   static iplist<ValueSubClass> &getList(ItemParentClass *Par) {
57     return Par->*(Par->getSublistAccess((ValueSubClass*)nullptr));
58   }
59 
getSymTab(ItemParentClass * Par)60   static ValueSymbolTable *getSymTab(ItemParentClass *Par) {
61     return Par ? toPtr(Par->getValueSymbolTable()) : nullptr;
62   }
63 
64   void addNodeToList(ValueSubClass *V);
65   void removeNodeFromList(ValueSubClass *V);
66   void transferNodesFromList(ilist_traits<ValueSubClass> &L2,
67                              ilist_iterator<ValueSubClass> first,
68                              ilist_iterator<ValueSubClass> last);
69 //private:
70   template<typename TPtr>
71   void setSymTabObject(TPtr *, TPtr);
toPtr(ValueSymbolTable * P)72   static ValueSymbolTable *toPtr(ValueSymbolTable *P) { return P; }
toPtr(ValueSymbolTable & R)73   static ValueSymbolTable *toPtr(ValueSymbolTable &R) { return &R; }
74 };
75 
76 } // End llvm namespace
77 
78 #endif
79