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

11 files changed, 54 insertions, 19 deletions

diff --git a/llvm/lib/CodeGen/CMakeLists.txt b/llvm/lib/CodeGen/CMakeLists.txt
index 7f7f5225180..f0b2dfe365b 100644
--- a/llvm/lib/CodeGen/CMakeLists.txt
+++ b/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
diff --git a/llvm/lib/CodeGen/ErlangGC.cpp b/llvm/lib/CodeGen/ErlangGC.cpp
index 30af07f1214..a40bbb5052a 100644
--- a/llvm/lib/CodeGen/ErlangGC.cpp
+++ b/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"
diff --git a/llvm/lib/CodeGen/GCMetadata.cpp b/llvm/lib/CodeGen/GCMetadata.cpp
index 7a61d61e7d0..ab8383a45c4 100644
--- a/llvm/lib/CodeGen/GCMetadata.cpp
+++ b/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);
+}
diff --git a/llvm/lib/CodeGen/GCRootLowering.cpp b/llvm/lib/CodeGen/GCRootLowering.cpp
index 7cb459874ef..ee89ac4e614 100644
--- a/llvm/lib/CodeGen/GCRootLowering.cpp
+++ b/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"
diff --git a/llvm/lib/CodeGen/GCStrategy.cpp b/llvm/lib/CodeGen/GCStrategy.cpp
new file mode 100644
index 00000000000..554d326942e
--- /dev/null
+++ b/llvm/lib/CodeGen/GCStrategy.cpp
@@ -0,0 +1,22 @@
+//===-- 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/CodeGen/GCStrategy.h"
+
+using namespace llvm;
+
+GCStrategy::GCStrategy()
+    : UseStatepoints(false), NeededSafePoints(0), CustomReadBarriers(false),
+      CustomWriteBarriers(false), CustomRoots(false), InitRoots(true),
+      UsesMetadata(false) {}
diff --git a/llvm/lib/CodeGen/OcamlGC.cpp b/llvm/lib/CodeGen/OcamlGC.cpp
index 164e3700909..17654a6ac3a 100644
--- a/llvm/lib/CodeGen/OcamlGC.cpp
+++ b/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;
 
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index 8c25783f4ea..699e2bbff6a 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/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"
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
index c56973a44fa..63f3d5eb407 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
+++ b/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"
diff --git a/llvm/lib/CodeGen/SelectionDAG/StatepointLowering.cpp b/llvm/lib/CodeGen/SelectionDAG/StatepointLowering.cpp
index 94f09bdc2f9..d3090a96845 100644
--- a/llvm/lib/CodeGen/SelectionDAG/StatepointLowering.cpp
+++ b/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"
diff --git a/llvm/lib/CodeGen/ShadowStackGC.cpp b/llvm/lib/CodeGen/ShadowStackGC.cpp
index 163d0efc07a..e4a389195ee 100644
--- a/llvm/lib/CodeGen/ShadowStackGC.cpp
+++ b/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"
diff --git a/llvm/lib/CodeGen/StatepointExampleGC.cpp b/llvm/lib/CodeGen/StatepointExampleGC.cpp
index 67f40c826fa..95dfd75018c 100644
--- a/llvm/lib/CodeGen/StatepointExampleGC.cpp
+++ b/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"