Revert GCStrategy ownership changes

This change reverts the interesting parts of 226311 (and 227046).  This change introduced two problems, and I've been convinced that an alternate approach is preferrable anyways.

The bugs were:
- Registery appears to require all users be within the same linkage unit.  After this change, asking for "statepoint-example" in Transform/ would sometimes get you nullptr, whereas asking the same question in CodeGen would return the right GCStrategy.  The correct long term fix is to get rid of the utter hack which is Registry, but I don't have time for that right now.  227046 appears to have been an attempt to fix this, but I don't believe it does so completely.
- GCMetadataPrinter::finishAssembly was being called more than once per GCStrategy.  Each Strategy was being added to the GCModuleInfo multiple times.

Once I get time again, I'm going to split GCModuleInfo into the gc.root specific part and a GCStrategy owning Analysis pass.  I'm probably also going to kill off the Registry.  Once that's done, I'll move the new GCStrategyAnalysis and all built in GCStrategies into Analysis.  (As original suggested by Chandler.)  This will accomplish my original goal of being able to access GCStrategy from Transform/  without adding all of the builtin GCs to IR/.  

llvm-svn: 227109

5 files changed, 0 insertions, 65 deletions

diff --git a/llvm/lib/IR/CMakeLists.txt b/llvm/lib/IR/CMakeLists.txt
index 621c7ca9224..1a210e05827 100644
--- a/llvm/lib/IR/CMakeLists.txt
+++ b/llvm/lib/IR/CMakeLists.txt
@@ -17,7 +17,6 @@ add_llvm_library(LLVMCore
   Dominators.cpp
   Function.cpp
   GCOV.cpp
-  GCStrategy.cpp
   GVMaterializer.cpp
   Globals.cpp
   IRBuilder.cpp
diff --git a/llvm/lib/IR/Function.cpp b/llvm/lib/IR/Function.cpp
index ddfbaf7a187..070513edef2 100644
--- a/llvm/lib/IR/Function.cpp
+++ b/llvm/lib/IR/Function.cpp
@@ -386,12 +386,6 @@ void Function::clearGC() {
   }
 }
 
-GCStrategy *Function::getGCStrategy() const {
-  // Lookup the GCStrategy (which is owned by the Context), given the name of
-  // the GC in question.
-  return getContext().pImpl->getGCStrategy(getGC());
-}
-
 /// copyAttributesFrom - copy all additional attributes (those not needed to
 /// create a Function) from the Function Src to this one.
 void Function::copyAttributesFrom(const GlobalValue *Src) {
diff --git a/llvm/lib/IR/GCStrategy.cpp b/llvm/lib/IR/GCStrategy.cpp
deleted file mode 100644
index b451310f7f0..00000000000
--- a/llvm/lib/IR/GCStrategy.cpp
+++ /dev/null
@@ -1,24 +0,0 @@
-//===-- GCStrategy.cpp - Garbage Collector Description --------------------===//
-//
-//                     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 policy object GCStrategy which describes the
-// behavior of a given garbage collector.
-//
-//===----------------------------------------------------------------------===//
-
-#include "llvm/IR/GCStrategy.h"
-
-template class llvm::Registry<llvm::GCStrategy>;
-
-using namespace llvm;
-
-GCStrategy::GCStrategy()
-    : UseStatepoints(false), NeededSafePoints(0), CustomReadBarriers(false),
-      CustomWriteBarriers(false), CustomRoots(false), InitRoots(true),
-      UsesMetadata(false) {}
diff --git a/llvm/lib/IR/LLVMContextImpl.cpp b/llvm/lib/IR/LLVMContextImpl.cpp
index 3370bdb0f88..d717b92d9fe 100644
--- a/llvm/lib/IR/LLVMContextImpl.cpp
+++ b/llvm/lib/IR/LLVMContextImpl.cpp
@@ -15,7 +15,6 @@
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/IR/Attributes.h"
 #include "llvm/IR/DiagnosticInfo.h"
-#include "llvm/IR/GCStrategy.h"
 #include "llvm/IR/Module.h"
 #include <algorithm>
 using namespace llvm;
@@ -239,25 +238,3 @@ void GetElementPtrConstantExpr::anchor() { }
 
 void CompareConstantExpr::anchor() { }
 
-GCStrategy *LLVMContextImpl::getGCStrategy(const StringRef Name) {
-  // TODO: Arguably, just doing a linear search would be faster for small N
-  auto NMI = GCStrategyMap.find(Name);
-  if (NMI != GCStrategyMap.end())
-    return NMI->getValue();
-  
-  for (auto& Entry : GCRegistry::entries()) {
-    if (Name == Entry.getName()) {
-      std::unique_ptr<GCStrategy> S = Entry.instantiate();
-      S->Name = Name;
-      GCStrategyMap[Name] = S.get();
-      GCStrategyList.push_back(std::move(S));
-      return GCStrategyList.back().get();
-    }
-  }
-
-  // No GCStrategy found for that name, error reporting is the job of our
-  // callers. 
-  return nullptr;
-}
-
-
diff --git a/llvm/lib/IR/LLVMContextImpl.h b/llvm/lib/IR/LLVMContextImpl.h
index 12b150741dd..e4e9f8f2a45 100644
--- a/llvm/lib/IR/LLVMContextImpl.h
+++ b/llvm/lib/IR/LLVMContextImpl.h
@@ -457,17 +457,6 @@ public:
   int getOrAddScopeRecordIdxEntry(MDNode *N, int ExistingIdx);
   int getOrAddScopeInlinedAtIdxEntry(MDNode *Scope, MDNode *IA,int ExistingIdx);
 
-  /// An owning list of all GCStrategies which have been created
-  SmallVector<std::unique_ptr<GCStrategy>, 1> GCStrategyList;
-  /// A helper map to speedup lookups into the above list
-  StringMap<GCStrategy*> GCStrategyMap;
-
-  /// Lookup the GCStrategy object associated with the given gc name.  If one
-  /// can't be found, returns nullptr.  The lifetime of the returned objects
-  /// is dictated by the lifetime of the associated context.  No caller should
-  /// attempt to delete the returned objects.
-  GCStrategy *getGCStrategy(const StringRef Name);
-  
   LLVMContextImpl(LLVMContext &C);
   ~LLVMContextImpl();