From 5df1207c2cf57a98763c28c8534230726ca8fc3a Mon Sep 17 00:00:00 2001
From: Chandler Carruth <chandlerc@gmail.com>
Date: Sun, 16 Aug 2015 06:35:19 +0000
Subject: [PATCH] Revert r244127: [PM] Remove a failed attempt to port the
 CallGraph analysis ...

It turns out that we *do* need the old CallGraph ported to the new pass
manager. There are times where this model of a call graph is really
superior to the one provided by the LazyCallGraph. For example,
GlobalsModRef very specifically needs the model provided by CallGraph.

While here, I've tried to make the move semantics actually work. =]

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@245170 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/llvm/Analysis/CallGraph.h | 24 +++++++++++++++++++++++-
 lib/Analysis/IPA/CallGraph.cpp    | 15 +++++++++++++++
 2 files changed, 38 insertions(+), 1 deletion(-)

diff --git a/include/llvm/Analysis/CallGraph.h b/include/llvm/Analysis/CallGraph.h
index 651d1901f3e..5562e9b9465 100644
--- a/include/llvm/Analysis/CallGraph.h
+++ b/include/llvm/Analysis/CallGraph.h
@@ -105,7 +105,8 @@ class CallGraph {
   void addToCallGraph(Function *F);
 
 public:
-  CallGraph(Module &M);
+  explicit CallGraph(Module &M);
+  CallGraph(CallGraph &&Arg);
   ~CallGraph();
 
   void print(raw_ostream &OS) const;
@@ -288,6 +289,27 @@ private:
   void allReferencesDropped() { NumReferences = 0; }
 };
 
+/// \brief An analysis pass to compute the \c CallGraph for a \c Module.
+///
+/// This class implements the concept of an analysis pass used by the \c
+/// ModuleAnalysisManager to run an analysis over a module and cache the
+/// resulting data.
+class CallGraphAnalysis {
+public:
+  /// \brief A formulaic typedef to inform clients of the result type.
+  typedef CallGraph Result;
+
+  static void *ID() { return (void *)&PassID; }
+
+  /// \brief Compute the \c CallGraph for the module \c M.
+  ///
+  /// The real work here is done in the \c CallGraph constructor.
+  CallGraph run(Module *M) { return CallGraph(*M); }
+
+private:
+  static char PassID;
+};
+
 /// \brief The \c ModulePass which wraps up a \c CallGraph and the logic to
 /// build it.
 ///
diff --git a/lib/Analysis/IPA/CallGraph.cpp b/lib/Analysis/IPA/CallGraph.cpp
index 46c044a3843..083b22d0170 100644
--- a/lib/Analysis/IPA/CallGraph.cpp
+++ b/lib/Analysis/IPA/CallGraph.cpp
@@ -32,6 +32,15 @@ CallGraph::CallGraph(Module &M)
     Root = ExternalCallingNode;
 }
 
+CallGraph::CallGraph(CallGraph &&Arg)
+    : M(Arg.M), FunctionMap(std::move(Arg.FunctionMap)), Root(Arg.Root),
+      ExternalCallingNode(Arg.ExternalCallingNode),
+      CallsExternalNode(std::move(Arg.CallsExternalNode)) {
+  Arg.FunctionMap.clear();
+  Arg.Root = nullptr;
+  Arg.ExternalCallingNode = nullptr;
+}
+
 CallGraph::~CallGraph() {
   // CallsExternalNode is not in the function map, delete it explicitly.
   if (CallsExternalNode)
@@ -252,6 +261,12 @@ void CallGraphNode::replaceCallEdge(CallSite CS,
   }
 }
 
+//===----------------------------------------------------------------------===//
+// Out-of-line definitions of CallGraphAnalysis class members.
+//
+
+char CallGraphAnalysis::PassID;
+
 //===----------------------------------------------------------------------===//
 // Implementations of the CallGraphWrapperPass class methods.
 //
-- 
2.34.1