From d257f7d96b414682834f1eb5aa4d9ea00f6761be Mon Sep 17 00:00:00 2001
From: Gabor Greif <ggreif@gmail.com>
Date: Fri, 27 Mar 2009 22:28:33 +0000
Subject: [PATCH] "ghostify" the ilist<Function> sentinel

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67872 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/llvm/Module.h | 17 ++++++++++++++---
 lib/VMCore/Module.cpp |  8 --------
 2 files changed, 14 insertions(+), 11 deletions(-)

diff --git a/include/llvm/Module.h b/include/llvm/Module.h
index 9d0b2b62f27..9c8607a188a 100644
--- a/include/llvm/Module.h
+++ b/include/llvm/Module.h
@@ -28,9 +28,20 @@ class FunctionType;
 
 template<> struct ilist_traits<Function>
   : public SymbolTableListTraits<Function, Module> {
-  // createSentinel is used to create a node that marks the end of the list.
-  static Function *createSentinel();
-  static void destroySentinel(Function *F) { delete F; }
+
+  // createSentinel is used to get hold of the node that marks the end of the
+  // list... (same trick used here as in ilist_traits<Instruction>)
+  Function *createSentinel() const {
+    return static_cast<Function*>(&Sentinel);
+  }
+  static void destroySentinel(Function*) {}
+
+  Function *provideInitialHead() const { return createSentinel(); }
+  Function *ensureHead(Function*) const { return createSentinel(); }
+  static void noteHead(Function*, Function*) {}
+
+private:
+  mutable ilist_node<Function> Sentinel;
 };
 template<> struct ilist_traits<GlobalVariable>
   : public SymbolTableListTraits<GlobalVariable, Module> {
diff --git a/lib/VMCore/Module.cpp b/lib/VMCore/Module.cpp
index 25d297a03e3..a598005e2a8 100644
--- a/lib/VMCore/Module.cpp
+++ b/lib/VMCore/Module.cpp
@@ -29,14 +29,6 @@ using namespace llvm;
 // Methods to implement the globals and functions lists.
 //
 
-Function *ilist_traits<Function>::createSentinel() {
-  FunctionType *FTy =
-    FunctionType::get(Type::VoidTy, std::vector<const Type*>(), false);
-  Function *Ret = Function::Create(FTy, GlobalValue::ExternalLinkage);
-  // This should not be garbage monitored.
-  LeakDetector::removeGarbageObject(Ret);
-  return Ret;
-}
 GlobalVariable *ilist_traits<GlobalVariable>::createSentinel() {
   GlobalVariable *Ret = new GlobalVariable(Type::Int32Ty, false,
                                            GlobalValue::ExternalLinkage);