IR: Create SymbolTableList wrapper around iplist, NFC

Create `SymbolTableList`, a wrapper around `iplist` for lists that
automatically manage a symbol table.  This commit reduces a ton of code
duplication between the six traits classes that were used previously.

As a drive by, reduce the number of template parameters from 2 to 1 by
using a SymbolTableListParentType metafunction (I originally had this as
a separate commit, but it touched most of the same lines so I squashed
them).

I'm in the process of trying to remove the UB in `createSentinel()` (see
the FIXMEs I added for `ilist_embedded_sentinel_traits` and
`ilist_half_embedded_sentinel_traits`).  My eventual goal is to separate
the list logic into a base class layer that knows nothing about (and
isn't templated on) the downcasted nodes -- removing the need to invoke
UB -- but for now I'm just trying to get a handle on all the current use
cases (and cleaning things up as I see them).

Besides these six SymbolTable lists, there are two others that use the
addNode/removeNode/transferNodes() hooks: the `MachineInstruction` and
`MachineBasicBlock` lists.  Ideally there'll be a way to factor these
hooks out of the low-level API entirely, but I'm not quite there yet.

llvm-svn: 249602

1 files changed, 14 insertions, 16 deletions

diff --git a/llvm/lib/IR/SymbolTableListTraitsImpl.h b/llvm/lib/IR/SymbolTableListTraitsImpl.h
index 4d17d75859c..e7fa8ba58f4 100644
--- a/llvm/lib/IR/SymbolTableListTraitsImpl.h
+++ b/llvm/lib/IR/SymbolTableListTraitsImpl.h
@@ -24,10 +24,10 @@ 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) {
+template <typename ValueSubClass>
+template <typename TPtr>
+void SymbolTableListTraits<ValueSubClass>::setSymTabObject(TPtr *Dest,
+                                                           TPtr Src) {
   // Get the old symtab and value list before doing the assignment.
   ValueSymbolTable *OldST = getSymTab(getListOwner());
 
@@ -41,7 +41,7 @@ void SymbolTableListTraits<ValueSubClass,ItemParentClass>
   if (OldST == NewST) return;
   
   // Move all the elements from the old symtab to the new one.
-  iplist<ValueSubClass> &ItemList = getList(getListOwner());
+  ListTy &ItemList = getList(getListOwner());
   if (ItemList.empty()) return;
   
   if (OldST) {
@@ -60,9 +60,8 @@ void SymbolTableListTraits<ValueSubClass,ItemParentClass>
   
 }
 
-template<typename ValueSubClass, typename ItemParentClass>
-void SymbolTableListTraits<ValueSubClass,ItemParentClass>
-::addNodeToList(ValueSubClass *V) {
+template <typename ValueSubClass>
+void SymbolTableListTraits<ValueSubClass>::addNodeToList(ValueSubClass *V) {
   assert(!V->getParent() && "Value already in a container!!");
   ItemParentClass *Owner = getListOwner();
   V->setParent(Owner);
@@ -71,20 +70,19 @@ void SymbolTableListTraits<ValueSubClass,ItemParentClass>
       ST->reinsertValue(V);
 }
 
-template<typename ValueSubClass, typename ItemParentClass>
-void SymbolTableListTraits<ValueSubClass,ItemParentClass>
-::removeNodeFromList(ValueSubClass *V) {
+template <typename ValueSubClass>
+void SymbolTableListTraits<ValueSubClass>::removeNodeFromList(
+    ValueSubClass *V) {
   V->setParent(nullptr);
   if (V->hasName())
     if (ValueSymbolTable *ST = 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) {
+template <typename ValueSubClass>
+void SymbolTableListTraits<ValueSubClass>::transferNodesFromList(
+    SymbolTableListTraits &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...