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

This reapplies 4f03258 (and follow up patches 26fc07d, a001cc0,
c9bc242, and fd174f0), which were reverted in 212cdc9 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 d0052eb. This patch also
restricts construction of the UnwindInfoManager object to Apple platforms (as
it won't be used on other platforms).

Author: lhames

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 @@ class JITDylib : public ThreadSafeRefCountedBase<JITDylib>,
 
   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 @@ class SelfExecutorProcessControl : public ExecutorProcessControl,
                           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 @@ class MachOLinkGraphBuilder {
   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);
   }