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

llvm/include/llvm/CodeGen/GCMetadata.h

@@ -34,9 +34,10 @@
 #define LLVM_CODEGEN_GCMETADATA_H
 
 #include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/StringMap.h"
+#include "llvm/CodeGen/GCStrategy.h"
 #include "llvm/IR/DebugLoc.h"
-#include "llvm/IR/GCStrategy.h"
 #include "llvm/Pass.h"
 #include <memory>
 
@@ -151,11 +152,17 @@ public:
 /// Records both the function level information used by GCRoots and a
 /// cache of the 'active' gc strategy objects for the current Module.
 class GCModuleInfo : public ImmutablePass {
-  /// A list of GCStrategies which are active in this Module.  These are
-  /// not owning pointers.
-  std::vector<GCStrategy *> StrategyList;
+  /// 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;
 
 public:
+  /// Lookup the GCStrategy object associated with the given gc name.
+  /// Objects are owned internally; No caller should attempt to delete the
+  /// returned objects. 
+  GCStrategy *getGCStrategy(const StringRef Name);
+  
   /// List of per function info objects.  In theory, Each of these
   /// may be associated with a different GC.
   typedef std::vector<std::unique_ptr<GCFunctionInfo>> FuncInfoVec;
@@ -173,7 +180,7 @@ private:
   finfo_map_type FInfoMap;
 
 public:
-  typedef std::vector<GCStrategy *>::const_iterator iterator;
+  typedef SmallVector<std::unique_ptr<GCStrategy>,1>::const_iterator iterator;
 
   static char ID;
 
@@ -186,8 +193,8 @@ public:
 
   /// begin/end - Iterators for used strategies.
   ///
-  iterator begin() const { return StrategyList.begin(); }
-  iterator end() const { return StrategyList.end(); }
+  iterator begin() const { return GCStrategyList.begin(); }
+  iterator end() const { return GCStrategyList.end(); }
 
   /// get - Look up function metadata.  This is currently assumed
   /// have the side effect of initializing the associated GCStrategy.  That

llvm/include/llvm/CodeGen/GCMetadataPrinter.h

@@ -21,7 +21,7 @@
 #define LLVM_CODEGEN_GCMETADATAPRINTER_H
 
 #include "llvm/CodeGen/GCMetadata.h"
-#include "llvm/IR/GCStrategy.h"
+#include "llvm/CodeGen/GCStrategy.h"
 #include "llvm/Support/Registry.h"
 
 namespace llvm {

llvm/include/llvm/CodeGen/GCStrategy.h

@@ -1,4 +1,4 @@
-//===-- llvm/IR/GCStrategy.h - Garbage collection ----------*- C++ -*-===//
+//===-- llvm/CodeGen/GCStrategy.h - Garbage collection ----------*- C++ -*-===//
 //
 //                     The LLVM Compiler Infrastructure
 //
@@ -78,7 +78,7 @@ enum PointKind {
 class GCStrategy {
 private:
   std::string Name;
-  friend class LLVMContextImpl;
+  friend class GCModuleInfo;
 
 protected:
   bool UseStatepoints; /// Uses gc.statepoints as opposed to gc.roots,
@@ -188,9 +188,6 @@ public:
 /// register your GCMetadataPrinter subclass with the
 /// GCMetadataPrinterRegistery as well.
 typedef Registry<GCStrategy> GCRegistry;
-
-/// GCStrategy is instantiated in GCStrategy.cpp.
-extern template class Registry<GCStrategy>;
 }
 
 #endif

llvm/include/llvm/IR/Function.h

@@ -29,7 +29,6 @@
 namespace llvm {
 
 class FunctionType;
-class GCStrategy;  
 class LLVMContext;
 
 // Traits for intrusive list of basic blocks...
@@ -226,10 +225,6 @@ public:
   void setGC(const char *Str);
   void clearGC();
 
-  /// Returns the GCStrategy associated with the specified garbage collector
-  /// algorithm or nullptr if one is not set.
-  GCStrategy *getGCStrategy() const;
-
   /// @brief adds the attribute to the list of attributes.
   void addAttribute(unsigned i, Attribute::AttrKind attr);
 

llvm/lib/CodeGen/CMakeLists.txt

@@ -23,6 +23,7 @@ add_llvm_library(LLVMCodeGen
   GCMetadata.cpp
   GCMetadataPrinter.cpp
   GCRootLowering.cpp
+  GCStrategy.cpp
   GlobalMerge.cpp
   IfConversion.cpp
   InlineSpiller.cpp

llvm/lib/CodeGen/ErlangGC.cpp

@@ -16,7 +16,7 @@
 
 #include "llvm/CodeGen/GCs.h"
 #include "llvm/CodeGen/MachineInstrBuilder.h"
-#include "llvm/IR/GCStrategy.h"
+#include "llvm/CodeGen/GCStrategy.h"
 #include "llvm/MC/MCContext.h"
 #include "llvm/MC/MCSymbol.h"
 #include "llvm/Target/TargetInstrInfo.h"

llvm/lib/CodeGen/GCMetadata.cpp

@@ -14,8 +14,8 @@
 #include "llvm/CodeGen/GCMetadata.h"
 #include "llvm/CodeGen/MachineFrameInfo.h"
 #include "llvm/CodeGen/Passes.h"
+#include "llvm/CodeGen/GCStrategy.h"
 #include "llvm/IR/Function.h"
-#include "llvm/IR/GCStrategy.h"
 #include "llvm/MC/MCSymbol.h"
 #include "llvm/Pass.h"
 #include "llvm/Support/Debug.h"
@@ -66,15 +66,7 @@ GCFunctionInfo &GCModuleInfo::getFunctionInfo(const Function &F) {
   if (I != FInfoMap.end())
     return *I->second;
 
-  GCStrategy *S = F.getGCStrategy();
-  if (!S) {
-    std::string error = std::string("unsupported GC: ") + F.getGC();
-    report_fatal_error(error);
-  }
-  // Save the fact this strategy is associated with this module.  Note that
-  // these are non-owning references, the GCStrategy remains owned by the
-  // Context.
-  StrategyList.push_back(S);
+  GCStrategy *S = getGCStrategy(F.getGC());
   Functions.push_back(make_unique<GCFunctionInfo>(F, *S));
   GCFunctionInfo *GFI = Functions.back().get();
   FInfoMap[&F] = GFI;
@@ -84,7 +76,7 @@ GCFunctionInfo &GCModuleInfo::getFunctionInfo(const Function &F) {
 void GCModuleInfo::clear() {
   Functions.clear();
   FInfoMap.clear();
-  StrategyList.clear();
+  GCStrategyList.clear();
 }
 
 // -----------------------------------------------------------------------------
@@ -159,3 +151,23 @@ bool Printer::doFinalization(Module &M) {
   GMI->clear();
   return false;
 }
+
+
+GCStrategy *GCModuleInfo::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();
+    }
+  }
+
+  report_fatal_error(std::string("unsupported GC: ") + Name);
+}

llvm/lib/CodeGen/GCRootLowering.cpp

@@ -16,9 +16,9 @@
 #include "llvm/CodeGen/MachineFunctionPass.h"
 #include "llvm/CodeGen/MachineInstrBuilder.h"
 #include "llvm/CodeGen/MachineModuleInfo.h"
+#include "llvm/CodeGen/GCStrategy.h"
 #include "llvm/CodeGen/Passes.h"
 #include "llvm/IR/Dominators.h"
-#include "llvm/IR/GCStrategy.h"
 #include "llvm/IR/IntrinsicInst.h"
 #include "llvm/IR/Module.h"
 #include "llvm/Support/Debug.h"

llvm/lib/CodeGen/GCStrategy.cpp

@@ -12,9 +12,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "llvm/IR/GCStrategy.h"
-
-template class llvm::Registry<llvm::GCStrategy>;
+#include "llvm/CodeGen/GCStrategy.h"
 
 using namespace llvm;
 

llvm/lib/CodeGen/OcamlGC.cpp

@@ -15,7 +15,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/CodeGen/GCs.h"
-#include "llvm/IR/GCStrategy.h"
+#include "llvm/CodeGen/GCStrategy.h"
 
 using namespace llvm;
 

llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp

@@ -26,6 +26,7 @@
 #include "llvm/CodeGen/FastISel.h"
 #include "llvm/CodeGen/FunctionLoweringInfo.h"
 #include "llvm/CodeGen/GCMetadata.h"
+#include "llvm/CodeGen/GCStrategy.h"
 #include "llvm/CodeGen/MachineFrameInfo.h"
 #include "llvm/CodeGen/MachineFunction.h"
 #include "llvm/CodeGen/MachineInstrBuilder.h"
@@ -40,7 +41,6 @@
 #include "llvm/IR/DebugInfo.h"
 #include "llvm/IR/DerivedTypes.h"
 #include "llvm/IR/Function.h"
-#include "llvm/IR/GCStrategy.h"
 #include "llvm/IR/GlobalVariable.h"
 #include "llvm/IR/InlineAsm.h"
 #include "llvm/IR/Instructions.h"

llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp

@@ -11,6 +11,7 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "llvm/CodeGen/GCStrategy.h"
 #include "llvm/CodeGen/SelectionDAGISel.h"
 #include "ScheduleDAGSDNodes.h"
 #include "SelectionDAGBuilder.h"
@@ -35,7 +36,6 @@
 #include "llvm/IR/Constants.h"
 #include "llvm/IR/DebugInfo.h"
 #include "llvm/IR/Function.h"
-#include "llvm/IR/GCStrategy.h"
 #include "llvm/IR/InlineAsm.h"
 #include "llvm/IR/Instructions.h"
 #include "llvm/IR/IntrinsicInst.h"

llvm/lib/CodeGen/SelectionDAG/StatepointLowering.cpp

@@ -18,10 +18,10 @@
 #include "llvm/ADT/Statistic.h"
 #include "llvm/CodeGen/GCMetadata.h"
 #include "llvm/CodeGen/FunctionLoweringInfo.h"
+#include "llvm/CodeGen/GCStrategy.h"
 #include "llvm/CodeGen/SelectionDAG.h"
 #include "llvm/CodeGen/StackMaps.h"
 #include "llvm/IR/CallingConv.h"
-#include "llvm/IR/GCStrategy.h"
 #include "llvm/IR/Instructions.h"
 #include "llvm/IR/IntrinsicInst.h"
 #include "llvm/IR/Intrinsics.h"

llvm/lib/CodeGen/ShadowStackGC.cpp

@@ -26,9 +26,9 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/CodeGen/GCs.h"
+#include "llvm/CodeGen/GCStrategy.h"
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/IR/CallSite.h"
-#include "llvm/IR/GCStrategy.h"
 #include "llvm/IR/IRBuilder.h"
 #include "llvm/IR/IntrinsicInst.h"
 #include "llvm/IR/Module.h"

llvm/lib/CodeGen/StatepointExampleGC.cpp

@@ -16,7 +16,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "llvm/IR/GCStrategy.h"
+#include "llvm/CodeGen/GCStrategy.h"
 #include "llvm/IR/DerivedTypes.h"
 #include "llvm/IR/Value.h"
 

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

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) {

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;
-}
-
-

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();