[GC] Consolidate all built in GCs into a single file [NFC]

Combine a bunch of small files into a single, still rather small, file.  The primary purpose of this is to get all of the static initializers into a single file so as to have a well defined order of initialization.  

llvm-svn: 258109

8 files changed, 145 insertions, 252 deletions

diff --git a/llvm/lib/CodeGen/BuiltinGCs.cpp b/llvm/lib/CodeGen/BuiltinGCs.cpp
new file mode 100644
index 00000000000..ff7c99de042
--- /dev/null
+++ b/llvm/lib/CodeGen/BuiltinGCs.cpp
@@ -0,0 +1,139 @@
+//===-- BuiltinGCs.cpp - Boilerplate for our built in GC types --*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains the boilerplate required to define our various built in
+// gc lowering strategies.  
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/CodeGen/GCs.h"
+#include "llvm/CodeGen/GCStrategy.h"
+
+using namespace llvm;
+
+namespace {
+
+/// An example GC which attempts to be compatibile with Erlang/OTP garbage
+/// collector.
+///
+/// The frametable emitter is in ErlangGCPrinter.cpp.
+class ErlangGC : public GCStrategy {
+public:
+  ErlangGC() {
+    InitRoots = false;
+    NeededSafePoints = 1 << GC::PostCall;
+    UsesMetadata = true;
+    CustomRoots = false;
+  }
+};
+
+/// An example GC which attempts to be compatible with Objective Caml 3.10.0
+///
+/// The frametable emitter is in OcamlGCPrinter.cpp.
+class OcamlGC : public GCStrategy {
+public:
+  OcamlGC() {
+    NeededSafePoints = 1 << GC::PostCall;
+    UsesMetadata = true;
+  }
+};
+
+/// A GC strategy for uncooperative targets.  This implements lowering for the
+/// llvm.gc* intrinsics for targets that do not natively support them (which
+/// includes the C backend). Note that the code generated is not quite as
+/// efficient as algorithms which generate stack maps to identify roots.
+///
+/// In order to support this particular transformation, all stack roots are
+/// coallocated in the stack. This allows a fully target-independent stack map
+/// while introducing only minor runtime overhead.
+class ShadowStackGC : public GCStrategy {
+public:
+  ShadowStackGC() {
+    InitRoots = true;
+    CustomRoots = true;
+  }
+};
+
+/// A GCStrategy which serves as an example for the usage of a statepoint based
+/// lowering strategy.  This GCStrategy is intended to suitable as a default
+/// implementation usable with any collector which can consume the standard
+/// stackmap format generated by statepoints, uses the default addrespace to
+/// distinguish between gc managed and non-gc managed pointers, and has
+/// reasonable relocation semantics.
+class StatepointGC : public GCStrategy {
+public:
+  StatepointGC() {
+    UseStatepoints = true;
+    // These options are all gc.root specific, we specify them so that the
+    // gc.root lowering code doesn't run.
+    InitRoots = false;
+    NeededSafePoints = 0;
+    UsesMetadata = false;
+    CustomRoots = false;
+  }
+  Optional<bool> isGCManagedPointer(const Type *Ty) const override {
+    // Method is only valid on pointer typed values.
+    const PointerType *PT = cast<PointerType>(Ty);
+    // For the sake of this example GC, we arbitrarily pick addrspace(1) as our
+    // GC managed heap.  We know that a pointer into this heap needs to be
+    // updated and that no other pointer does.  Note that addrspace(1) is used
+    // only as an example, it has no special meaning, and is not reserved for
+    // GC usage.
+    return (1 == PT->getAddressSpace());
+  }
+};
+
+/// A GCStrategy for the CoreCLR Runtime. The strategy is similar to
+/// Statepoint-example GC, but differs from it in certain aspects, such as:
+/// 1) Base-pointers need not be explicitly tracked and reported for
+///    interior pointers
+/// 2) Uses a different format for encoding stack-maps
+/// 3) Location of Safe-point polls: polls are only needed before loop-back
+///    edges and before tail-calls (not needed at function-entry)
+///
+/// The above differences in behavior are to be implemented in upcoming
+/// checkins.
+class CoreCLRGC : public GCStrategy {
+public:
+  CoreCLRGC() {
+    UseStatepoints = true;
+    // These options are all gc.root specific, we specify them so that the
+    // gc.root lowering code doesn't run.
+    InitRoots = false;
+    NeededSafePoints = 0;
+    UsesMetadata = false;
+    CustomRoots = false;
+  }
+  Optional<bool> isGCManagedPointer(const Type *Ty) const override {
+    // Method is only valid on pointer typed values.
+    const PointerType *PT = cast<PointerType>(Ty);
+    // We pick addrspace(1) as our GC managed heap.
+    return (1 == PT->getAddressSpace());
+  }
+};
+}
+
+// Register all the above so that they can be found at runtime.  Note that
+// these static initializers are important since the registration list is
+// constructed from their storage.
+static GCRegistry::Add<ErlangGC> A("erlang",
+                                   "erlang-compatible garbage collector");
+static GCRegistry::Add<OcamlGC> B("ocaml", "ocaml 3.10-compatible GC");
+static GCRegistry::Add<ShadowStackGC>
+    C("shadow-stack", "Very portable GC for uncooperative code generators");
+static GCRegistry::Add<StatepointGC> D("statepoint-example",
+                                       "an example strategy for statepoint");
+static GCRegistry::Add<CoreCLRGC> E("coreclr", "CoreCLR-compatible GC");
+
+// Provide hooks to ensure the containing library is fully loaded.
+void llvm::linkErlangGC() {}
+void llvm::linkOcamlGC() {}
+void llvm::linkShadowStackGC() {}
+void llvm::linkStatepointExampleGC() {}
+void llvm::linkCoreCLRGC() {}
diff --git a/llvm/lib/CodeGen/CMakeLists.txt b/llvm/lib/CodeGen/CMakeLists.txt
index 358a49f55f5..b7c1bd32d38 100644
--- a/llvm/lib/CodeGen/CMakeLists.txt
+++ b/llvm/lib/CodeGen/CMakeLists.txt
@@ -10,18 +10,17 @@ add_llvm_library(LLVMCodeGen
   AtomicExpandPass.cpp
   BasicTargetTransformInfo.cpp
   BranchFolding.cpp
+  BuiltinGCs.cpp
   CalcSpillWeights.cpp
   CallingConvLower.cpp
   CodeGen.cpp
   CodeGenPrepare.cpp
-  CoreCLRGC.cpp
   CriticalAntiDepBreaker.cpp
   DFAPacketizer.cpp
   DeadMachineInstructionElim.cpp
   DwarfEHPrepare.cpp
   EarlyIfConversion.cpp
   EdgeBundles.cpp
-  ErlangGC.cpp
   ExecutionDepsFix.cpp
   ExpandISelPseudos.cpp
   ExpandPostRAPseudos.cpp
@@ -84,7 +83,6 @@ add_llvm_library(LLVMCodeGen
   MachineVerifier.cpp
   MIRPrinter.cpp
   MIRPrintingPass.cpp
-  OcamlGC.cpp
   OptimizePHIs.cpp
   PHIElimination.cpp
   PHIEliminationUtils.cpp
@@ -109,7 +107,6 @@ add_llvm_library(LLVMCodeGen
   ScheduleDAGPrinter.cpp
   ScoreboardHazardRecognizer.cpp
   ShrinkWrap.cpp
-  ShadowStackGC.cpp
   ShadowStackGCLowering.cpp
   SjLjEHPrepare.cpp
   SlotIndexes.cpp
@@ -120,7 +117,6 @@ add_llvm_library(LLVMCodeGen
   StackSlotColoring.cpp
   StackMapLivenessAnalysis.cpp
   StackMaps.cpp
-  StatepointExampleGC.cpp
   TailDuplication.cpp
   TargetFrameLoweringImpl.cpp
   TargetInstrInfo.cpp
diff --git a/llvm/lib/CodeGen/CoreCLRGC.cpp b/llvm/lib/CodeGen/CoreCLRGC.cpp
deleted file mode 100644
index ff7c0d5dc0a..00000000000
--- a/llvm/lib/CodeGen/CoreCLRGC.cpp
+++ /dev/null
@@ -1,54 +0,0 @@
-//===-- CoreCLRGC.cpp - CoreCLR Runtime GC Strategy -----------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This file contains a GCStrategy for the CoreCLR Runtime.
-// The strategy is similar to Statepoint-example GC, but differs from it in
-// certain aspects, such as:
-// 1) Base-pointers need not be explicitly tracked and reported for
-//    interior pointers
-// 2) Uses a different format for encoding stack-maps
-// 3) Location of Safe-point polls: polls are only needed before loop-back edges
-//    and before tail-calls (not needed at function-entry)
-//
-// The above differences in behavior are to be implemented in upcoming checkins.
-//
-//===----------------------------------------------------------------------===//
-
-#include "llvm/CodeGen/GCStrategy.h"
-#include "llvm/IR/DerivedTypes.h"
-#include "llvm/IR/Value.h"
-
-using namespace llvm;
-
-namespace {
-class CoreCLRGC : public GCStrategy {
-public:
-  CoreCLRGC() {
-    UseStatepoints = true;
-    // These options are all gc.root specific, we specify them so that the
-    // gc.root lowering code doesn't run.
-    InitRoots = false;
-    NeededSafePoints = 0;
-    UsesMetadata = false;
-    CustomRoots = false;
-  }
-  Optional<bool> isGCManagedPointer(const Type *Ty) const override {
-    // Method is only valid on pointer typed values.
-    const PointerType *PT = cast<PointerType>(Ty);
-    // We pick addrspace(1) as our GC managed heap.
-    return (1 == PT->getAddressSpace());
-  }
-};
-}
-
-static GCRegistry::Add<CoreCLRGC> X("coreclr", "CoreCLR-compatible GC");
-
-namespace llvm {
-void linkCoreCLRGC() {}
-}
diff --git a/llvm/lib/CodeGen/ErlangGC.cpp b/llvm/lib/CodeGen/ErlangGC.cpp
deleted file mode 100644
index 024946d1436..00000000000
--- a/llvm/lib/CodeGen/ErlangGC.cpp
+++ /dev/null
@@ -1,46 +0,0 @@
-//===-- ErlangGC.cpp - Erlang/OTP GC strategy -------------------*- C++ -*-===//
-//
-//                     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 Erlang/OTP runtime-compatible garbage collector
-// (e.g. defines safe points, root initialization etc.)
-//
-// The frametable emitter is in ErlangGCPrinter.cpp.
-//
-//===----------------------------------------------------------------------===//
-
-#include "llvm/CodeGen/GCs.h"
-#include "llvm/CodeGen/GCStrategy.h"
-#include "llvm/CodeGen/MachineInstrBuilder.h"
-#include "llvm/MC/MCContext.h"
-#include "llvm/MC/MCSymbol.h"
-#include "llvm/Target/TargetInstrInfo.h"
-#include "llvm/Target/TargetMachine.h"
-#include "llvm/Target/TargetSubtargetInfo.h"
-
-using namespace llvm;
-
-namespace {
-
-class ErlangGC : public GCStrategy {
-public:
-  ErlangGC();
-};
-}
-
-static GCRegistry::Add<ErlangGC> X("erlang",
-                                   "erlang-compatible garbage collector");
-
-void llvm::linkErlangGC() {}
-
-ErlangGC::ErlangGC() {
-  InitRoots = false;
-  NeededSafePoints = 1 << GC::PostCall;
-  UsesMetadata = true;
-  CustomRoots = false;
-}
diff --git a/llvm/lib/CodeGen/OcamlGC.cpp b/llvm/lib/CodeGen/OcamlGC.cpp
deleted file mode 100644
index 17654a6ac3a..00000000000
--- a/llvm/lib/CodeGen/OcamlGC.cpp
+++ /dev/null
@@ -1,36 +0,0 @@
-//===-- OcamlGC.cpp - Ocaml frametable GC strategy ------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This file implements lowering for the llvm.gc* intrinsics compatible with
-// Objective Caml 3.10.0, which uses a liveness-accurate static stack map.
-//
-// The frametable emitter is in OcamlGCPrinter.cpp.
-//
-//===----------------------------------------------------------------------===//
-
-#include "llvm/CodeGen/GCs.h"
-#include "llvm/CodeGen/GCStrategy.h"
-
-using namespace llvm;
-
-namespace {
-class OcamlGC : public GCStrategy {
-public:
-  OcamlGC();
-};
-}
-
-static GCRegistry::Add<OcamlGC> X("ocaml", "ocaml 3.10-compatible GC");
-
-void llvm::linkOcamlGC() {}
-
-OcamlGC::OcamlGC() {
-  NeededSafePoints = 1 << GC::PostCall;
-  UsesMetadata = true;
-}
diff --git a/llvm/lib/CodeGen/ShadowStackGC.cpp b/llvm/lib/CodeGen/ShadowStackGC.cpp
deleted file mode 100644
index b12e943eb35..00000000000
--- a/llvm/lib/CodeGen/ShadowStackGC.cpp
+++ /dev/null
@@ -1,55 +0,0 @@
-//===-- ShadowStackGC.cpp - GC support for uncooperative targets ----------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This file implements lowering for the llvm.gc* intrinsics for targets that do
-// not natively support them (which includes the C backend). Note that the code
-// generated is not quite as efficient as algorithms which generate stack maps
-// to identify roots.
-//
-// This pass implements the code transformation described in this paper:
-//   "Accurate Garbage Collection in an Uncooperative Environment"
-//   Fergus Henderson, ISMM, 2002
-//
-// In runtime/GC/SemiSpace.cpp is a prototype runtime which is compatible with
-// ShadowStackGC.
-//
-// In order to support this particular transformation, all stack roots are
-// coallocated in the stack. This allows a fully target-independent stack map
-// while introducing only minor runtime overhead.
-//
-//===----------------------------------------------------------------------===//
-
-#include "llvm/CodeGen/GCs.h"
-#include "llvm/ADT/StringExtras.h"
-#include "llvm/CodeGen/GCStrategy.h"
-#include "llvm/IR/CallSite.h"
-#include "llvm/IR/IRBuilder.h"
-#include "llvm/IR/IntrinsicInst.h"
-#include "llvm/IR/Module.h"
-
-using namespace llvm;
-
-#define DEBUG_TYPE "shadowstackgc"
-
-namespace {
-class ShadowStackGC : public GCStrategy {
-public:
-  ShadowStackGC();
-};
-}
-
-static GCRegistry::Add<ShadowStackGC>
-    X("shadow-stack", "Very portable GC for uncooperative code generators");
-
-void llvm::linkShadowStackGC() {}
-
-ShadowStackGC::ShadowStackGC() {
-  InitRoots = true;
-  CustomRoots = true;
-}
diff --git a/llvm/lib/CodeGen/ShadowStackGCLowering.cpp b/llvm/lib/CodeGen/ShadowStackGCLowering.cpp
index 878eeeed0f6..1efc440cd70 100644
--- a/llvm/lib/CodeGen/ShadowStackGCLowering.cpp
+++ b/llvm/lib/CodeGen/ShadowStackGCLowering.cpp
@@ -8,7 +8,11 @@
 //===----------------------------------------------------------------------===//
 //
 // This file contains the custom lowering code required by the shadow-stack GC
-// strategy.  
+// strategy.
+//
+// This pass implements the code transformation described in this paper:
+//   "Accurate Garbage Collection in an Uncooperative Environment"
+//   Fergus Henderson, ISMM, 2002
 //
 //===----------------------------------------------------------------------===//
 
diff --git a/llvm/lib/CodeGen/StatepointExampleGC.cpp b/llvm/lib/CodeGen/StatepointExampleGC.cpp
deleted file mode 100644
index 3f60e18fafa..00000000000
--- a/llvm/lib/CodeGen/StatepointExampleGC.cpp
+++ /dev/null
@@ -1,55 +0,0 @@
-//===-- StatepointDefaultGC.cpp - The default statepoint GC strategy ------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This file contains a GCStrategy which serves as an example for the usage
-// of a statepoint based lowering strategy.  This GCStrategy is intended to
-// suitable as a default implementation usable with any collector which can
-// consume the standard stackmap format generated by statepoints, uses the
-// default addrespace to distinguish between gc managed and non-gc managed
-// pointers, and has reasonable relocation semantics.
-//
-//===----------------------------------------------------------------------===//
-
-#include "llvm/CodeGen/GCStrategy.h"
-#include "llvm/IR/DerivedTypes.h"
-#include "llvm/IR/Value.h"
-
-using namespace llvm;
-
-namespace {
-class StatepointGC : public GCStrategy {
-public:
-  StatepointGC() {
-    UseStatepoints = true;
-    // These options are all gc.root specific, we specify them so that the
-    // gc.root lowering code doesn't run.
-    InitRoots = false;
-    NeededSafePoints = 0;
-    UsesMetadata = false;
-    CustomRoots = false;
-  }
-  Optional<bool> isGCManagedPointer(const Type *Ty) const override {
-    // Method is only valid on pointer typed values.
-    const PointerType *PT = cast<PointerType>(Ty);
-    // For the sake of this example GC, we arbitrarily pick addrspace(1) as our
-    // GC managed heap.  We know that a pointer into this heap needs to be
-    // updated and that no other pointer does.  Note that addrspace(1) is used
-    // only as an example, it has no special meaning, and is not reserved for
-    // GC usage.
-    return (1 == PT->getAddressSpace());
-  }
-};
-}
-
-static GCRegistry::Add<StatepointGC> X("statepoint-example",
-                                       "an example strategy for statepoint");
-
-namespace llvm {
-void linkStatepointExampleGC() {}
-}