[ORC][JITLink] Switch to unique ownership for EHFrameRegistrars.

This will make stateful registrars (e.g. a future TargetProcessControl based
registrar) easier to deal with.

llvm/include/llvm/ExecutionEngine/JITLink/EHFrameSupport.h

@@ -42,32 +42,11 @@ public:
 /// Registers / Deregisters EH-frames in the current process.
 class InProcessEHFrameRegistrar final : public EHFrameRegistrar {
 public:
-  /// Get a reference to the InProcessEHFrameRegistrar singleton.
-  static InProcessEHFrameRegistrar &getInstance();
-
-  InProcessEHFrameRegistrar(const InProcessEHFrameRegistrar &) = delete;
-  InProcessEHFrameRegistrar &
-  operator=(const InProcessEHFrameRegistrar &) = delete;
-
-  InProcessEHFrameRegistrar(InProcessEHFrameRegistrar &&) = delete;
-  InProcessEHFrameRegistrar &operator=(InProcessEHFrameRegistrar &&) = delete;
-
   Error registerEHFrames(JITTargetAddress EHFrameSectionAddr,
-                         size_t EHFrameSectionSize) override {
-    return registerEHFrameSection(
-        jitTargetAddressToPointer<void *>(EHFrameSectionAddr),
-        EHFrameSectionSize);
-  }
+                         size_t EHFrameSectionSize) override;
 
   Error deregisterEHFrames(JITTargetAddress EHFrameSectionAddr,
-                           size_t EHFrameSectionSize) override {
-    return deregisterEHFrameSection(
-        jitTargetAddressToPointer<void *>(EHFrameSectionAddr),
-        EHFrameSectionSize);
-  }
-
-private:
-  InProcessEHFrameRegistrar();
+                           size_t EHFrameSectionSize) override;
 };
 
 using StoreFrameRangeFunction =

llvm/include/llvm/ExecutionEngine/Orc/ObjectLinkingLayer.h

@@ -177,7 +177,8 @@ private:
 
 class EHFrameRegistrationPlugin : public ObjectLinkingLayer::Plugin {
 public:
-  EHFrameRegistrationPlugin(jitlink::EHFrameRegistrar &Registrar);
+  EHFrameRegistrationPlugin(
+      std::unique_ptr<jitlink::EHFrameRegistrar> Registrar);
   Error notifyEmitted(MaterializationResponsibility &MR) override;
   void modifyPassConfig(MaterializationResponsibility &MR, const Triple &TT,
                         jitlink::PassConfiguration &PassConfig) override;
@@ -192,7 +193,7 @@ private:
   };
 
   std::mutex EHFramePluginMutex;
-  jitlink::EHFrameRegistrar &Registrar;
+  std::unique_ptr<jitlink::EHFrameRegistrar> Registrar;
   DenseMap<MaterializationResponsibility *, EHFrameRange> InProcessLinks;
   DenseMap<VModuleKey, EHFrameRange> TrackedEHFrameRanges;
   std::vector<EHFrameRange> UntrackedEHFrameRanges;

llvm/lib/ExecutionEngine/JITLink/EHFrameSupport.cpp

@@ -763,12 +763,19 @@ Error deregisterEHFrameSection(const void *EHFrameSectionAddr,
 
 EHFrameRegistrar::~EHFrameRegistrar() {}
 
-InProcessEHFrameRegistrar &InProcessEHFrameRegistrar::getInstance() {
-  static InProcessEHFrameRegistrar Instance;
-  return Instance;
+Error InProcessEHFrameRegistrar::registerEHFrames(
+    JITTargetAddress EHFrameSectionAddr, size_t EHFrameSectionSize) {
+  return registerEHFrameSection(
+      jitTargetAddressToPointer<void *>(EHFrameSectionAddr),
+      EHFrameSectionSize);
 }
 
-InProcessEHFrameRegistrar::InProcessEHFrameRegistrar() {}
+Error InProcessEHFrameRegistrar::deregisterEHFrames(
+    JITTargetAddress EHFrameSectionAddr, size_t EHFrameSectionSize) {
+  return deregisterEHFrameSection(
+      jitTargetAddressToPointer<void *>(EHFrameSectionAddr),
+      EHFrameSectionSize);
+}
 
 LinkGraphPassFunction
 createEHFrameRecorderPass(const Triple &TT,

llvm/lib/ExecutionEngine/Orc/LLJIT.cpp

@@ -984,7 +984,7 @@ Error LLJITBuilderState::prepareForConstruction() {
           ObjLinkingLayer = std::make_unique<ObjectLinkingLayer>(
               ES, std::make_unique<jitlink::InProcessMemoryManager>());
         ObjLinkingLayer->addPlugin(std::make_unique<EHFrameRegistrationPlugin>(
-            jitlink::InProcessEHFrameRegistrar::getInstance()));
+            std::make_unique<jitlink::InProcessEHFrameRegistrar>()));
         return std::move(ObjLinkingLayer);
       };
     }

llvm/lib/ExecutionEngine/Orc/ObjectLinkingLayer.cpp

@@ -536,8 +536,8 @@ Error ObjectLinkingLayer::removeAllModules() {
 }
 
 EHFrameRegistrationPlugin::EHFrameRegistrationPlugin(
-    EHFrameRegistrar &Registrar)
-    : Registrar(Registrar) {}
+    std::unique_ptr<EHFrameRegistrar> Registrar)
+    : Registrar(std::move(Registrar)) {}
 
 void EHFrameRegistrationPlugin::modifyPassConfig(
     MaterializationResponsibility &MR, const Triple &TT,
@@ -572,7 +572,7 @@ Error EHFrameRegistrationPlugin::notifyEmitted(
   else
     UntrackedEHFrameRanges.push_back(EHFrameRange);
 
-  return Registrar.registerEHFrames(EHFrameRange.Addr, EHFrameRange.Size);
+  return Registrar->registerEHFrames(EHFrameRange.Addr, EHFrameRange.Size);
 }
 
 Error EHFrameRegistrationPlugin::notifyRemovingModule(VModuleKey K) {
@@ -587,7 +587,7 @@ Error EHFrameRegistrationPlugin::notifyRemovingModule(VModuleKey K) {
 
   TrackedEHFrameRanges.erase(EHFrameRangeItr);
 
-  return Registrar.deregisterEHFrames(EHFrameRange.Addr, EHFrameRange.Size);
+  return Registrar->deregisterEHFrames(EHFrameRange.Addr, EHFrameRange.Size);
 }
 
 Error EHFrameRegistrationPlugin::notifyRemovingAllModules() {
@@ -608,9 +608,8 @@ Error EHFrameRegistrationPlugin::notifyRemovingAllModules() {
     auto EHFrameRange = EHFrameRanges.back();
     assert(EHFrameRange.Addr && "Untracked eh-frame range must not be null");
     EHFrameRanges.pop_back();
-    Err = joinErrors(std::move(Err),
-                     Registrar.deregisterEHFrames(EHFrameRange.Addr,
-                                                  EHFrameRange.Size));
+    Err = joinErrors(std::move(Err), Registrar->deregisterEHFrames(
+                                         EHFrameRange.Addr, EHFrameRange.Size));
   }
 
   return Err;

llvm/tools/llvm-jitlink/llvm-jitlink.cpp

@@ -618,7 +618,7 @@ Session::Session(Triple TT, uint64_t PageSize, Error &Err)
 
   if (!NoExec && !TT.isOSWindows())
     ObjLayer.addPlugin(std::make_unique<EHFrameRegistrationPlugin>(
-        InProcessEHFrameRegistrar::getInstance()));
+        std::make_unique<InProcessEHFrameRegistrar>()));
 
   ObjLayer.addPlugin(std::make_unique<JITLinkSessionPlugin>(*this));