1 //===-- llvm/SymbolTableListTraitsImpl.h - Implementation ------*- 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 implements the stickier parts of the SymbolTableListTraits class,
10 // and is explicitly instantiated where needed to avoid defining all this code
11 // in a widely used header.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #ifndef LLVM_LIB_IR_SYMBOLTABLELISTTRAITSIMPL_H
16 #define LLVM_LIB_IR_SYMBOLTABLELISTTRAITSIMPL_H
17 
18 #include "llvm/IR/SymbolTableListTraits.h"
19 #include "llvm/IR/ValueSymbolTable.h"
20 
21 namespace llvm {
22 
23 /// Notify basic blocks when an instruction is inserted.
24 template <typename ParentClass>
25 inline void invalidateParentIListOrdering(ParentClass *Parent) {}
26 template <> void invalidateParentIListOrdering(BasicBlock *BB);
27 
28 /// setSymTabObject - This is called when (f.e.) the parent of a basic block
29 /// changes.  This requires us to remove all the instruction symtab entries from
30 /// the current function and reinsert them into the new function.
31 template <typename ValueSubClass>
32 template <typename TPtr>
33 void SymbolTableListTraits<ValueSubClass>::setSymTabObject(TPtr *Dest,
34                                                            TPtr Src) {
35   // Get the old symtab and value list before doing the assignment.
36   ValueSymbolTable *OldST = getSymTab(getListOwner());
37 
38   // Do it.
39   *Dest = Src;
40 
41   // Get the new SymTab object.
42   ValueSymbolTable *NewST = getSymTab(getListOwner());
43 
44   // If there is nothing to do, quick exit.
45   if (OldST == NewST) return;
46 
47   // Move all the elements from the old symtab to the new one.
48   ListTy &ItemList = getList(getListOwner());
49   if (ItemList.empty()) return;
50 
51   if (OldST) {
52     // Remove all entries from the previous symtab.
53     for (auto I = ItemList.begin(); I != ItemList.end(); ++I)
54       if (I->hasName())
55         OldST->removeValueName(I->getValueName());
56   }
57 
58   if (NewST) {
59     // Add all of the items to the new symtab.
60     for (auto I = ItemList.begin(); I != ItemList.end(); ++I)
61       if (I->hasName())
62         NewST->reinsertValue(&*I);
63   }
64 
65 }
66 
67 template <typename ValueSubClass>
68 void SymbolTableListTraits<ValueSubClass>::addNodeToList(ValueSubClass *V) {
69   assert(!V->getParent() && "Value already in a container!!");
70   ItemParentClass *Owner = getListOwner();
71   V->setParent(Owner);
72   invalidateParentIListOrdering(Owner);
73   if (V->hasName())
74     if (ValueSymbolTable *ST = getSymTab(Owner))
75       ST->reinsertValue(V);
76 }
77 
78 template <typename ValueSubClass>
79 void SymbolTableListTraits<ValueSubClass>::removeNodeFromList(
80     ValueSubClass *V) {
81   V->setParent(nullptr);
82   if (V->hasName())
83     if (ValueSymbolTable *ST = getSymTab(getListOwner()))
84       ST->removeValueName(V->getValueName());
85 }
86 
87 template <typename ValueSubClass>
88 void SymbolTableListTraits<ValueSubClass>::transferNodesFromList(
89     SymbolTableListTraits &L2, iterator first, iterator last) {
90   // Transfering nodes, even within the same BB, invalidates the ordering. The
91   // list that we removed the nodes from still has a valid ordering.
92   ItemParentClass *NewIP = getListOwner();
93   invalidateParentIListOrdering(NewIP);
94 
95   // Nothing else needs to be done if we're reording nodes within the same list.
96   ItemParentClass *OldIP = L2.getListOwner();
97   if (NewIP == OldIP)
98     return;
99 
100   // We only have to update symbol table entries if we are transferring the
101   // instructions to a different symtab object...
102   ValueSymbolTable *NewST = getSymTab(NewIP);
103   ValueSymbolTable *OldST = getSymTab(OldIP);
104   if (NewST != OldST) {
105     for (; first != last; ++first) {
106       ValueSubClass &V = *first;
107       bool HasName = V.hasName();
108       if (OldST && HasName)
109         OldST->removeValueName(V.getValueName());
110       V.setParent(NewIP);
111       if (NewST && HasName)
112         NewST->reinsertValue(&V);
113     }
114   } else {
115     // Just transferring between blocks in the same function, simply update the
116     // parent fields in the instructions...
117     for (; first != last; ++first)
118       first->setParent(NewIP);
119   }
120 }
121 
122 } // End llvm namespace
123 
124 #endif
125