SymbolTableListTraitsImpl.h

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//===-- llvm/SymbolTableListTraitsImpl.h - Implementation ------*- C++ -*--===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the stickier parts of the SymbolTableListTraits class,
// and is explicitly instantiated where needed to avoid defining all this code
// in a widely used header.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_LIB_IR_SYMBOLTABLELISTTRAITSIMPL_H
#define LLVM_LIB_IR_SYMBOLTABLELISTTRAITSIMPL_H

#include "llvm/IR/SymbolTableListTraits.h"
#include "llvm/IR/ValueSymbolTable.h"

namespace llvm {

/// setSymTabObject - This is called when (f.e.) the parent of a basic block
/// changes.  This requires us to remove all the instruction symtab entries from
/// the current function and reinsert them into the new function.
template<typename ValueSubClass, typename ItemParentClass>
template<typename TPtr>
void SymbolTableListTraits<ValueSubClass,ItemParentClass>
::setSymTabObject(TPtr *Dest, TPtr Src) {
  // Get the old symtab and value list before doing the assignment.
  ValueSymbolTable *OldST = TraitsClass::getSymTab(getListOwner());

  // Do it.
  *Dest = Src;
  
  // Get the new SymTab object.
  ValueSymbolTable *NewST = TraitsClass::getSymTab(getListOwner());
  
  // If there is nothing to do, quick exit.
  if (OldST == NewST) return;
  
  // Move all the elements from the old symtab to the new one.
  iplist<ValueSubClass> &ItemList = TraitsClass::getList(getListOwner());
  if (ItemList.empty()) return;
  
  if (OldST) {
    // Remove all entries from the previous symtab.
    for (typename iplist<ValueSubClass>::iterator I = ItemList.begin();
         I != ItemList.end(); ++I)
      if (I->hasName())
        OldST->removeValueName(I->getValueName());
  }

  if (NewST) {
    // Add all of the items to the new symtab.
    for (typename iplist<ValueSubClass>::iterator I = ItemList.begin();
         I != ItemList.end(); ++I)
      if (I->hasName())
        NewST->reinsertValue(I);
  }
  
}

template<typename ValueSubClass, typename ItemParentClass>
void SymbolTableListTraits<ValueSubClass,ItemParentClass>
::addNodeToList(ValueSubClass *V) {
  assert(!V->getParent() && "Value already in a container!!");
  ItemParentClass *Owner = getListOwner();
  V->setParent(Owner);
  if (V->hasName())
    if (ValueSymbolTable *ST = TraitsClass::getSymTab(Owner))
      ST->reinsertValue(V);
}

template<typename ValueSubClass, typename ItemParentClass>
void SymbolTableListTraits<ValueSubClass,ItemParentClass>
::removeNodeFromList(ValueSubClass *V) {
  V->setParent(nullptr);
  if (V->hasName())
    if (ValueSymbolTable *ST = TraitsClass::getSymTab(getListOwner()))
      ST->removeValueName(V->getValueName());
}

template<typename ValueSubClass, typename ItemParentClass>
void SymbolTableListTraits<ValueSubClass,ItemParentClass>
::transferNodesFromList(ilist_traits<ValueSubClass> &L2,
                        ilist_iterator<ValueSubClass> first,
                        ilist_iterator<ValueSubClass> last) {
  // We only have to do work here if transferring instructions between BBs
  ItemParentClass *NewIP = getListOwner(), *OldIP = L2.getListOwner();
  if (NewIP == OldIP) return;  // No work to do at all...

  // We only have to update symbol table entries if we are transferring the
  // instructions to a different symtab object...
  ValueSymbolTable *NewST = TraitsClass::getSymTab(NewIP);
  ValueSymbolTable *OldST = TraitsClass::getSymTab(OldIP);
  if (NewST != OldST) {
    for (; first != last; ++first) {
      ValueSubClass &V = *first;
      bool HasName = V.hasName();
      if (OldST && HasName)
        OldST->removeValueName(V.getValueName());
      V.setParent(NewIP);
      if (NewST && HasName)
        NewST->reinsertValue(&V);
    }
  } else {
    // Just transferring between blocks in the same function, simply update the
    // parent fields in the instructions...
    for (; first != last; ++first)
      first->setParent(NewIP);
  }
}

} // End llvm namespace

#endif