Reapply "[ORC] Enable JIT support for the compact-unwind frame..." with fixes.

This reapplies 4f0325873f (and follow up patches 26fc07d5d8, a001cc0e6c,
c9bc242e38, and fd174f0ff3), which were reverted in 212cdc9a37 to
investigate bot failures (e.g.
https://lab.llvm.org/buildbot/#/builders/108/builds/8502)

The fix to address the bot failures was landed in d0052ebbe2. This patch also
restricts construction of the UnwindInfoManager object to Apple platforms (as
it won't be used on other platforms).

clang/test/Interpreter/simple-exception.cpp

@@ -1,7 +1,7 @@
 // clang-format off
 // UNSUPPORTED: system-aix
-// XFAIL for arm and arm64, or running on Windows.
-// XFAIL: target=arm{{.*}}, system-windows
+// XFAIL for arm, or running on Windows.
+// XFAIL: target=arm-{{.*}}, target=armv{{.*}}, system-windows
 // RUN: cat %s | clang-repl | FileCheck %s
 
 // Incompatible with msan. It passes with -O3 but fail -Oz. Interpreter

compiler-rt/lib/orc/macho_platform.cpp

@@ -557,6 +557,12 @@ Error MachOPlatformRuntimeState::registerObjectPlatformSections(
     return make_error<StringError>(ErrStream.str());
   }
 
+  ORC_RT_DEBUG({
+    printdbg("  UnwindInfo: %s, UseCallbackStyleUnwindInfo: %s\n",
+             UnwindInfo ? "true" : "false",
+             UseCallbackStyleUnwindInfo ? "true" : "false");
+  });
+
   if (UnwindInfo && UseCallbackStyleUnwindInfo) {
     ORC_RT_DEBUG({
       printdbg("  Registering new-style unwind info for:\n"

llvm/include/llvm/ExecutionEngine/Orc/Core.h

@@ -1204,8 +1204,13 @@ private:
 
   JITDylib(ExecutionSession &ES, std::string Name);
 
-  std::pair<AsynchronousSymbolQuerySet, std::shared_ptr<SymbolDependenceMap>>
-  IL_removeTracker(ResourceTracker &RT);
+  struct RemoveTrackerResult {
+    AsynchronousSymbolQuerySet QueriesToFail;
+    std::shared_ptr<SymbolDependenceMap> FailedSymbols;
+    std::vector<std::unique_ptr<MaterializationUnit>> DefunctMUs;
+  };
+
+  RemoveTrackerResult IL_removeTracker(ResourceTracker &RT);
 
   void transferTracker(ResourceTracker &DstRT, ResourceTracker &SrcRT);
 

llvm/include/llvm/ExecutionEngine/Orc/ExecutorProcessControl.h

@@ -20,6 +20,7 @@
 #include "llvm/ExecutionEngine/Orc/Shared/TargetProcessControlTypes.h"
 #include "llvm/ExecutionEngine/Orc/Shared/WrapperFunctionUtils.h"
 #include "llvm/ExecutionEngine/Orc/SymbolStringPool.h"
+#include "llvm/ExecutionEngine/Orc/TargetProcess/UnwindInfoManager.h"
 #include "llvm/ExecutionEngine/Orc/TaskDispatch.h"
 #include "llvm/Support/DynamicLibrary.h"
 #include "llvm/Support/MSVCErrorWorkarounds.h"
@@ -507,6 +508,9 @@ private:
                           SymbolLookupCompleteFn F) override;
 
   std::unique_ptr<jitlink::JITLinkMemoryManager> OwnedMemMgr;
+#ifdef __APPLE__
+  std::unique_ptr<UnwindInfoManager> UnwindInfoMgr;
+#endif // __APPLE__
   char GlobalManglingPrefix = 0;
 };
 

llvm/include/llvm/ExecutionEngine/Orc/Shared/OrcRTBridge.h

@@ -88,6 +88,15 @@ using SPSRunAsMainSignature = int64_t(shared::SPSExecutorAddr,
 using SPSRunAsVoidFunctionSignature = int32_t(shared::SPSExecutorAddr);
 using SPSRunAsIntFunctionSignature = int32_t(shared::SPSExecutorAddr, int32_t);
 } // end namespace rt
+
+namespace rt_alt {
+extern const char *UnwindInfoManagerInstanceName;
+extern const char *UnwindInfoManagerFindSectionsHelperName;
+extern const char *UnwindInfoManagerEnableWrapperName;
+extern const char *UnwindInfoManagerDisableWrapperName;
+extern const char *UnwindInfoManagerRegisterActionName;
+extern const char *UnwindInfoManagerDeregisterActionName;
+} // end namespace rt_alt
 } // end namespace orc
 } // end namespace llvm
 

llvm/lib/ExecutionEngine/JITLink/CMakeLists.txt

@@ -3,6 +3,7 @@ tablegen(LLVM COFFOptions.inc -gen-opt-parser-defs)
 add_public_tablegen_target(JITLinkTableGen)
 
 add_llvm_component_library(LLVMJITLink
+  CompactUnwindSupport.cpp
   DWARFRecordSectionSplitter.cpp
   EHFrameSupport.cpp
   JITLink.cpp

llvm/lib/ExecutionEngine/JITLink/MachOLinkGraphBuilder.cpp

@@ -733,121 +733,5 @@ Error MachOLinkGraphBuilder::graphifyCStringSection(
   return Error::success();
 }
 
-Error CompactUnwindSplitter::operator()(LinkGraph &G) {
-  auto *CUSec = G.findSectionByName(CompactUnwindSectionName);
-  if (!CUSec)
-    return Error::success();
-
-  if (!G.getTargetTriple().isOSBinFormatMachO())
-    return make_error<JITLinkError>(
-        "Error linking " + G.getName() +
-        ": compact unwind splitting not supported on non-macho target " +
-        G.getTargetTriple().str());
-
-  unsigned CURecordSize = 0;
-  unsigned PersonalityEdgeOffset = 0;
-  unsigned LSDAEdgeOffset = 0;
-  switch (G.getTargetTriple().getArch()) {
-  case Triple::aarch64:
-  case Triple::x86_64:
-    // 64-bit compact-unwind record format:
-    // Range start: 8 bytes.
-    // Range size:  4 bytes.
-    // CU encoding: 4 bytes.
-    // Personality: 8 bytes.
-    // LSDA:        8 bytes.
-    CURecordSize = 32;
-    PersonalityEdgeOffset = 16;
-    LSDAEdgeOffset = 24;
-    break;
-  default:
-    return make_error<JITLinkError>(
-        "Error linking " + G.getName() +
-        ": compact unwind splitting not supported on " +
-        G.getTargetTriple().getArchName());
-  }
-
-  std::vector<Block *> OriginalBlocks(CUSec->blocks().begin(),
-                                      CUSec->blocks().end());
-  LLVM_DEBUG({
-    dbgs() << "In " << G.getName() << " splitting compact unwind section "
-           << CompactUnwindSectionName << " containing "
-           << OriginalBlocks.size() << " initial blocks...\n";
-  });
-
-  while (!OriginalBlocks.empty()) {
-    auto *B = OriginalBlocks.back();
-    OriginalBlocks.pop_back();
-
-    if (B->getSize() == 0) {
-      LLVM_DEBUG({
-        dbgs() << "  Skipping empty block at "
-               << formatv("{0:x16}", B->getAddress()) << "\n";
-      });
-      continue;
-    }
-
-    unsigned NumBlocks = B->getSize() / CURecordSize;
-
-    LLVM_DEBUG({
-      dbgs() << "  Splitting block at " << formatv("{0:x16}", B->getAddress())
-             << " into " << NumBlocks << " compact unwind record(s)\n";
-    });
-
-    if (B->getSize() % CURecordSize)
-      return make_error<JITLinkError>(
-          "Error splitting compact unwind record in " + G.getName() +
-          ": block at " + formatv("{0:x}", B->getAddress()) + " has size " +
-          formatv("{0:x}", B->getSize()) +
-          " (not a multiple of CU record size of " +
-          formatv("{0:x}", CURecordSize) + ")");
-
-    auto Blocks =
-        G.splitBlock(*B, map_range(seq(1U, NumBlocks), [=](Edge::OffsetT Idx) {
-          return Idx * CURecordSize;
-        }));
-
-    for (auto *CURec : Blocks) {
-      bool AddedKeepAlive = false;
-
-      for (auto &E : CURec->edges()) {
-        if (E.getOffset() == 0) {
-          LLVM_DEBUG({
-            dbgs() << "    Updating compact unwind record at "
-                   << CURec->getAddress() << " to point to "
-                   << (E.getTarget().hasName() ? *E.getTarget().getName()
-                                               : StringRef())
-                   << " (at " << E.getTarget().getAddress() << ")\n";
-          });
-
-          if (E.getTarget().isExternal())
-            return make_error<JITLinkError>(
-                "Error adding keep-alive edge for compact unwind record at " +
-                formatv("{0:x}", CURec->getAddress()) + ": target " +
-                *E.getTarget().getName() + " is an external symbol");
-          auto &TgtBlock = E.getTarget().getBlock();
-          auto &CURecSym =
-              G.addAnonymousSymbol(*CURec, 0, CURecordSize, false, false);
-          TgtBlock.addEdge(Edge::KeepAlive, 0, CURecSym, 0);
-          AddedKeepAlive = true;
-        } else if (E.getOffset() != PersonalityEdgeOffset &&
-                   E.getOffset() != LSDAEdgeOffset)
-          return make_error<JITLinkError>(
-              "Unexpected edge at offset " + formatv("{0:x}", E.getOffset()) +
-              " in compact unwind record at " +
-              formatv("{0:x}", CURec->getAddress()));
-      }
-
-      if (!AddedKeepAlive)
-        return make_error<JITLinkError>(
-            "Error adding keep-alive edge for compact unwind record at " +
-            formatv("{0:x}", CURec->getAddress()) +
-            ": no outgoing target edge at offset 0");
-    }
-  }
-
-  return Error::success();
-}
-
 } // end namespace jitlink
 } // end namespace llvm

llvm/lib/ExecutionEngine/JITLink/MachOLinkGraphBuilder.h

@@ -236,17 +236,6 @@ private:
   StringMap<SectionParserFunction> CustomSectionParserFunctions;
 };
 
-/// A pass to split up __LD,__compact_unwind sections.
-class CompactUnwindSplitter {
-public:
-  CompactUnwindSplitter(StringRef CompactUnwindSectionName)
-      : CompactUnwindSectionName(CompactUnwindSectionName) {}
-  Error operator()(LinkGraph &G);
-
-private:
-  StringRef CompactUnwindSectionName;
-};
-
 } // end namespace jitlink
 } // end namespace llvm
 

llvm/lib/ExecutionEngine/JITLink/MachO_arm64.cpp

@@ -14,6 +14,7 @@
 #include "llvm/ExecutionEngine/JITLink/DWARFRecordSectionSplitter.h"
 #include "llvm/ExecutionEngine/JITLink/aarch64.h"
 
+#include "CompactUnwindSupport.h"
 #include "DefineExternalSectionStartAndEndSymbols.h"
 #include "MachOLinkGraphBuilder.h"
 
@@ -625,6 +626,27 @@ static Error applyPACSigningToModInitPointers(LinkGraph &G) {
   return Error::success();
 }
 
+struct CompactUnwindTraits_MachO_arm64
+    : public CompactUnwindTraits<CompactUnwindTraits_MachO_arm64,
+                                 /* PointerSize = */ 8> {
+  // FIXME: Reinstate once we no longer need the MSVC workaround. See
+  //        FIXME for CompactUnwindTraits in CompactUnwindSupport.h.
+  // constexpr static size_t PointerSize = 8;
+
+  constexpr static endianness Endianness = endianness::little;
+
+  constexpr static uint32_t EncodingModeMask = 0x0f000000;
+
+  using GOTManager = aarch64::GOTTableManager;
+
+  static bool encodingSpecifiesDWARF(uint32_t Encoding) {
+    constexpr uint32_t DWARFMode = 0x03000000;
+    return (Encoding & EncodingModeMask) == DWARFMode;
+  }
+
+  static bool encodingCannotBeMerged(uint32_t Encoding) { return false; }
+};
+
 void link_MachO_arm64(std::unique_ptr<LinkGraph> G,
                       std::unique_ptr<JITLinkContext> Ctx) {
 
@@ -637,16 +659,21 @@ void link_MachO_arm64(std::unique_ptr<LinkGraph> G,
     else
       Config.PrePrunePasses.push_back(markAllSymbolsLive);
 
-    // Add compact unwind splitter pass.
-    Config.PrePrunePasses.push_back(
-        CompactUnwindSplitter("__LD,__compact_unwind"));
-
     // Add eh-frame passes.
-    // FIXME: Prune eh-frames for which compact-unwind is available once
-    // we support compact-unwind registration with libunwind.
     Config.PrePrunePasses.push_back(createEHFrameSplitterPass_MachO_arm64());
     Config.PrePrunePasses.push_back(createEHFrameEdgeFixerPass_MachO_arm64());
 
+    // Create a compact-unwind manager for use in passes below.
+    auto CompactUnwindMgr =
+        std::make_shared<CompactUnwindManager<CompactUnwindTraits_MachO_arm64>>(
+            "__LD,__compact_unwind", "__TEXT,__unwind_info",
+            "__TEXT,__eh_frame");
+
+    // Add compact unwind prepare pass.
+    Config.PrePrunePasses.push_back([CompactUnwindMgr](LinkGraph &G) {
+      return CompactUnwindMgr->prepareForPrune(G);
+    });
+
     // Resolve any external section start / end symbols.
     Config.PostAllocationPasses.push_back(
         createDefineExternalSectionStartAndEndSymbolsPass(
@@ -663,6 +690,16 @@ void link_MachO_arm64(std::unique_ptr<LinkGraph> G,
       Config.PreFixupPasses.push_back(
           aarch64::lowerPointer64AuthEdgesToSigningFunction);
     }
+
+    // Reserve unwind-info space.
+    Config.PostPrunePasses.push_back([CompactUnwindMgr](LinkGraph &G) {
+      return CompactUnwindMgr->processAndReserveUnwindInfo(G);
+    });
+
+    // Translate compact-unwind to unwind-info.
+    Config.PreFixupPasses.push_back([CompactUnwindMgr](LinkGraph &G) {
+      return CompactUnwindMgr->writeUnwindInfo(G);
+    });
   }
 
   if (auto Err = Ctx->modifyPassConfig(*G, Config))

llvm/lib/ExecutionEngine/JITLink/MachO_x86_64.cpp

@@ -14,6 +14,7 @@
 #include "llvm/ExecutionEngine/JITLink/DWARFRecordSectionSplitter.h"
 #include "llvm/ExecutionEngine/JITLink/x86_64.h"
 
+#include "CompactUnwindSupport.h"
 #include "DefineExternalSectionStartAndEndSymbols.h"
 #include "MachOLinkGraphBuilder.h"
 
@@ -500,26 +501,56 @@ Expected<std::unique_ptr<LinkGraph>> createLinkGraphFromMachOObject_x86_64(
       .buildGraph();
 }
 
+struct CompactUnwindTraits_MachO_x86_64
+    : public CompactUnwindTraits<CompactUnwindTraits_MachO_x86_64,
+                                 /* PointerSize = */ 8> {
+  // FIXME: Reinstate once we no longer need the MSVC workaround. See
+  //        FIXME for CompactUnwindTraits in CompactUnwindSupport.h.
+  // constexpr static size_t PointerSize = 8;
+
+  constexpr static endianness Endianness = endianness::little;
+
+  constexpr static uint32_t EncodingModeMask = 0x0f000000;
+
+  using GOTManager = x86_64::GOTTableManager;
+
+  static bool encodingSpecifiesDWARF(uint32_t Encoding) {
+    constexpr uint32_t DWARFMode = 0x04000000;
+    return (Encoding & EncodingModeMask) == DWARFMode;
+  }
+
+  static bool encodingCannotBeMerged(uint32_t Encoding) {
+    constexpr uint32_t StackIndirectMode = 0x03000000;
+    return (Encoding & EncodingModeMask) == StackIndirectMode;
+  }
+};
+
 void link_MachO_x86_64(std::unique_ptr<LinkGraph> G,
                        std::unique_ptr<JITLinkContext> Ctx) {
 
   PassConfiguration Config;
 
   if (Ctx->shouldAddDefaultTargetPasses(G->getTargetTriple())) {
-    // Add eh-frame passes.
-    Config.PrePrunePasses.push_back(createEHFrameSplitterPass_MachO_x86_64());
-    Config.PrePrunePasses.push_back(createEHFrameEdgeFixerPass_MachO_x86_64());
-
-    // Add compact unwind splitter pass.
-    Config.PrePrunePasses.push_back(
-        CompactUnwindSplitter("__LD,__compact_unwind"));
-
     // Add a mark-live pass.
     if (auto MarkLive = Ctx->getMarkLivePass(G->getTargetTriple()))
       Config.PrePrunePasses.push_back(std::move(MarkLive));
     else
       Config.PrePrunePasses.push_back(markAllSymbolsLive);
 
+    // Add eh-frame passes.
+    Config.PrePrunePasses.push_back(createEHFrameSplitterPass_MachO_x86_64());
+    Config.PrePrunePasses.push_back(createEHFrameEdgeFixerPass_MachO_x86_64());
+
+    // Create a compact-unwind manager for use in passes below.
+    auto CompactUnwindMgr = std::make_shared<
+        CompactUnwindManager<CompactUnwindTraits_MachO_x86_64>>(
+        "__LD,__compact_unwind", "__TEXT,__unwind_info", "__TEXT,__eh_frame");
+
+    // Add compact unwind prepare pass.
+    Config.PrePrunePasses.push_back([CompactUnwindMgr](LinkGraph &G) {
+      return CompactUnwindMgr->prepareForPrune(G);
+    });
+
     // Resolve any external section start / end symbols.
     Config.PostAllocationPasses.push_back(
         createDefineExternalSectionStartAndEndSymbolsPass(
@@ -528,6 +559,16 @@ void link_MachO_x86_64(std::unique_ptr<LinkGraph> G,
     // Add an in-place GOT/Stubs pass.
     Config.PostPrunePasses.push_back(buildGOTAndStubs_MachO_x86_64);
 
+    // Reserve space for unwind-info.
+    Config.PostPrunePasses.push_back([CompactUnwindMgr](LinkGraph &G) {
+      return CompactUnwindMgr->processAndReserveUnwindInfo(G);
+    });
+
+    // Translate compact-unwind to unwind-info.
+    Config.PreFixupPasses.push_back([CompactUnwindMgr](LinkGraph &G) {
+      return CompactUnwindMgr->writeUnwindInfo(G);
+    });
+
     // Add GOT/Stubs optimizer pass.
     Config.PreFixupPasses.push_back(x86_64::optimizeGOTAndStubAccesses);
   }

llvm/lib/ExecutionEngine/Orc/CMakeLists.txt

@@ -57,6 +57,7 @@ add_llvm_component_library(LLVMOrcJIT
   ExecutorProcessControl.cpp
   TaskDispatch.cpp
   ThreadSafeModule.cpp
+  UnwindInfoRegistrationPlugin.cpp
   RedirectionManager.cpp
   JITLinkRedirectableSymbolManager.cpp
   ReOptimizeLayer.cpp

llvm/lib/ExecutionEngine/Orc/CompileUtils.cpp

@@ -33,6 +33,9 @@ irManglingOptionsFromTargetOptions(const TargetOptions &Opts) {
 
 /// Compile a Module to an ObjectFile.
 Expected<SimpleCompiler::CompileResult> SimpleCompiler::operator()(Module &M) {
+  if (M.getDataLayout().isDefault())
+    M.setDataLayout(TM.createDataLayout());
+
   CompileResult CachedObject = tryToLoadFromObjectCache(M);
   if (CachedObject)
     return std::move(CachedObject);

llvm/lib/ExecutionEngine/Orc/Core.cpp

@@ -1251,9 +1251,7 @@ JITDylib::JITDylib(ExecutionSession &ES, std::string Name)
   LinkOrder.push_back({this, JITDylibLookupFlags::MatchAllSymbols});
 }
 
-std::pair<JITDylib::AsynchronousSymbolQuerySet,
-          std::shared_ptr<SymbolDependenceMap>>
-JITDylib::IL_removeTracker(ResourceTracker &RT) {
+JITDylib::RemoveTrackerResult JITDylib::IL_removeTracker(ResourceTracker &RT) {
   // Note: Should be called under the session lock.
   assert(State != Closed && "JD is defunct");
 
@@ -1292,7 +1290,10 @@ JITDylib::IL_removeTracker(ResourceTracker &RT) {
       SymbolsToFail.push_back(Sym);
   }
 
-  auto Result = ES.IL_failSymbols(*this, std::move(SymbolsToFail));
+  auto [QueriesToFail, FailedSymbols] =
+      ES.IL_failSymbols(*this, std::move(SymbolsToFail));
+
+  std::vector<std::unique_ptr<MaterializationUnit>> DefunctMUs;
 
   // Removed symbols should be taken out of the table altogether.
   for (auto &Sym : SymbolsToRemove) {
@@ -1302,7 +1303,12 @@ JITDylib::IL_removeTracker(ResourceTracker &RT) {
     // Remove Materializer if present.
     if (I->second.hasMaterializerAttached()) {
       // FIXME: Should this discard the symbols?
-      UnmaterializedInfos.erase(Sym);
+      auto J = UnmaterializedInfos.find(Sym);
+      assert(J != UnmaterializedInfos.end() &&
+             "Symbol table indicates MU present, but no UMI record");
+      if (J->second->MU)
+        DefunctMUs.push_back(std::move(J->second->MU));
+      UnmaterializedInfos.erase(J);
     } else {
       assert(!UnmaterializedInfos.count(Sym) &&
              "Symbol has materializer attached");
@@ -1313,7 +1319,8 @@ JITDylib::IL_removeTracker(ResourceTracker &RT) {
 
   shrinkMaterializationInfoMemory();
 
-  return Result;
+  return {std::move(QueriesToFail), std::move(FailedSymbols),
+          std::move(DefunctMUs)};
 }
 
 void JITDylib::transferTracker(ResourceTracker &DstRT, ResourceTracker &SrcRT) {
@@ -2180,16 +2187,17 @@ Error ExecutionSession::removeResourceTracker(ResourceTracker &RT) {
   });
   std::vector<ResourceManager *> CurrentResourceManagers;
 
-  JITDylib::AsynchronousSymbolQuerySet QueriesToFail;
-  std::shared_ptr<SymbolDependenceMap> FailedSymbols;
+  JITDylib::RemoveTrackerResult R;
 
   runSessionLocked([&] {
     CurrentResourceManagers = ResourceManagers;
     RT.makeDefunct();
-    std::tie(QueriesToFail, FailedSymbols) =
-        RT.getJITDylib().IL_removeTracker(RT);
+    R = RT.getJITDylib().IL_removeTracker(RT);
   });
 
+  // Release any defunct MaterializationUnits.
+  R.DefunctMUs.clear();
+
   Error Err = Error::success();
 
   auto &JD = RT.getJITDylib();
@@ -2197,9 +2205,9 @@ Error ExecutionSession::removeResourceTracker(ResourceTracker &RT) {
     Err = joinErrors(std::move(Err),
                      L->handleRemoveResources(JD, RT.getKeyUnsafe()));
 
-  for (auto &Q : QueriesToFail)
-    Q->handleFailed(
-        make_error<FailedToMaterialize>(getSymbolStringPool(), FailedSymbols));
+  for (auto &Q : R.QueriesToFail)
+    Q->handleFailed(make_error<FailedToMaterialize>(getSymbolStringPool(),
+                                                    R.FailedSymbols));
 
   return Err;
 }

llvm/lib/ExecutionEngine/Orc/ExecutorProcessControl.cpp

@@ -45,6 +45,7 @@ SelfExecutorProcessControl::SelfExecutorProcessControl(
   this->DylibMgr = this;
   this->JDI = {ExecutorAddr::fromPtr(jitDispatchViaWrapperFunctionManager),
                ExecutorAddr::fromPtr(this)};
+
   if (this->TargetTriple.isOSBinFormatMachO())
     GlobalManglingPrefix = '_';
 
@@ -52,6 +53,12 @@ SelfExecutorProcessControl::SelfExecutorProcessControl(
       ExecutorAddr::fromPtr(&llvm_orc_registerEHFrameSectionWrapper);
   this->BootstrapSymbols[rt::DeregisterEHFrameSectionWrapperName] =
       ExecutorAddr::fromPtr(&llvm_orc_deregisterEHFrameSectionWrapper);
+
+#ifdef __APPLE__
+  this->UnwindInfoMgr = UnwindInfoManager::TryCreate();
+  if (this->UnwindInfoMgr)
+    this->UnwindInfoMgr->addBootstrapSymbols(this->BootstrapSymbols);
+#endif // __APPLE__
 }
 
 Expected<std::unique_ptr<SelfExecutorProcessControl>>

llvm/lib/ExecutionEngine/Orc/LLJIT.cpp

@@ -21,6 +21,7 @@
 #include "llvm/ExecutionEngine/Orc/ObjectTransformLayer.h"
 #include "llvm/ExecutionEngine/Orc/RTDyldObjectLinkingLayer.h"
 #include "llvm/ExecutionEngine/Orc/TargetProcess/RegisterEHFrames.h"
+#include "llvm/ExecutionEngine/Orc/UnwindInfoRegistrationPlugin.h"
 #include "llvm/ExecutionEngine/SectionMemoryManager.h"
 #include "llvm/IR/GlobalVariable.h"
 #include "llvm/IR/IRBuilder.h"
@@ -1220,12 +1221,28 @@ Expected<JITDylibSP> setUpGenericLLVMIRPlatform(LLJIT &J) {
 
   if (auto *OLL = dyn_cast<ObjectLinkingLayer>(&J.getObjLinkingLayer())) {
 
-    auto &ES = J.getExecutionSession();
-    if (auto EHFrameRegistrar = EPCEHFrameRegistrar::Create(ES))
-      OLL->addPlugin(std::make_unique<EHFrameRegistrationPlugin>(
-          ES, std::move(*EHFrameRegistrar)));
-    else
-      return EHFrameRegistrar.takeError();
+    bool CompactUnwindInfoSupported = false;
+
+    // Enable compact-unwind support if possible.
+    if (J.getTargetTriple().isOSDarwin() ||
+        J.getTargetTriple().isOSBinFormatMachO()) {
+      if (auto UIRP = UnwindInfoRegistrationPlugin::Create(
+              J.getIRCompileLayer(), PlatformJD)) {
+        CompactUnwindInfoSupported = true;
+        OLL->addPlugin(std::move(*UIRP));
+      } else
+        consumeError(UIRP.takeError());
+    }
+
+    // Otherwise fall back to standard unwind registration.
+    if (!CompactUnwindInfoSupported) {
+      auto &ES = J.getExecutionSession();
+      if (auto EHFrameRegistrar = EPCEHFrameRegistrar::Create(ES))
+        OLL->addPlugin(std::make_unique<EHFrameRegistrationPlugin>(
+            ES, std::move(*EHFrameRegistrar)));
+      else
+        return EHFrameRegistrar.takeError();
+    }
   }
 
   J.setPlatformSupport(

llvm/lib/ExecutionEngine/Orc/Shared/OrcRTBridge.cpp

@@ -64,5 +64,19 @@ const char *RunAsIntFunctionWrapperName =
     "__llvm_orc_bootstrap_run_as_int_function_wrapper";
 
 } // end namespace rt
+namespace rt_alt {
+const char *UnwindInfoManagerInstanceName =
+    "orc_rt_alt_UnwindInfoManager_Instance";
+const char *UnwindInfoManagerFindSectionsHelperName =
+    "orc_rt_alt_UnwindInfoManager_findSectionsHelper";
+const char *UnwindInfoManagerEnableWrapperName =
+    "orc_rt_alt_UnwindInfoManager_enable";
+const char *UnwindInfoManagerDisableWrapperName =
+    "orc_rt_alt_UnwindInfoManager_disable";
+const char *UnwindInfoManagerRegisterActionName =
+    "orc_rt_alt_UnwindInfoManager_register";
+const char *UnwindInfoManagerDeregisterActionName =
+    "orc_rt_alt_UnwindInfoManager_deregister";
+} // end namespace rt_alt
 } // end namespace orc
 } // end namespace llvm

llvm/lib/ExecutionEngine/Orc/TargetProcess/CMakeLists.txt

@@ -20,6 +20,7 @@ add_llvm_component_library(LLVMOrcTargetProcess
   SimpleExecutorMemoryManager.cpp
   SimpleRemoteEPCServer.cpp
   TargetExecutionUtils.cpp
+  UnwindInfoManager.cpp
 
   ADDITIONAL_HEADER_DIRS
   ${LLVM_MAIN_INCLUDE_DIR}/llvm/ExecutionEngine/Orc