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diff --git a/llvm/lib/ExecutionEngine/JITLink/COFFLinkGraphBuilder.h b/llvm/lib/ExecutionEngine/JITLink/COFFLinkGraphBuilder.h
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+++ b/llvm/lib/ExecutionEngine/JITLink/COFFLinkGraphBuilder.h
@@ -0,0 +1,199 @@
+//===----- COFFLinkGraphBuilder.h - COFF LinkGraph builder ----*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// Generic COFF LinkGraph building code.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LIB_EXECUTIONENGINE_JITLINK_COFFLINKGRAPHBUILDER_H
+#define LIB_EXECUTIONENGINE_JITLINK_COFFLINKGRAPHBUILDER_H
+
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/StringMap.h"
+#include "llvm/ExecutionEngine/JITLink/JITLink.h"
+#include "llvm/Object/COFF.h"
+
+#include "EHFrameSupportImpl.h"
+#include "JITLinkGeneric.h"
+
+#define DEBUG_TYPE "jitlink"
+
+#include <list>
+
+namespace llvm {
+namespace jitlink {
+
+class COFFLinkGraphBuilder {
+public:
+  virtual ~COFFLinkGraphBuilder();
+  Expected<std::unique_ptr<LinkGraph>> buildGraph();
+
+protected:
+  using COFFSectionIndex = int32_t;
+  using COFFSymbolIndex = int32_t;
+
+  COFFLinkGraphBuilder(const object::COFFObjectFile &Obj, Triple TT,
+                       LinkGraph::GetEdgeKindNameFunction GetEdgeKindName);
+
+  LinkGraph &getGraph() const { return *G; }
+
+  const object::COFFObjectFile &getObject() const { return Obj; }
+
+  virtual Error addRelocations() = 0;
+
+  Error graphifySections();
+  Error graphifySymbols();
+
+  void setGraphSymbol(COFFSectionIndex SecIndex, COFFSymbolIndex SymIndex,
+                      Symbol &Sym) {
+    assert(!GraphSymbols[SymIndex] && "Duplicate symbol at index");
+    GraphSymbols[SymIndex] = &Sym;
+    if (!COFF::isReservedSectionNumber(SecIndex))
+      SymbolSets[SecIndex].insert({Sym.getOffset(), &Sym});
+  }
+
+  Symbol *getGraphSymbol(COFFSymbolIndex SymIndex) const {
+    if (SymIndex < 0 ||
+        SymIndex >= static_cast<COFFSymbolIndex>(GraphSymbols.size()))
+      return nullptr;
+    return GraphSymbols[SymIndex];
+  }
+
+  void setGraphBlock(COFFSectionIndex SecIndex, Block *B) {
+    assert(!GraphBlocks[SecIndex] && "Duplicate section at index");
+    assert(!COFF::isReservedSectionNumber(SecIndex) && "Invalid section index");
+    GraphBlocks[SecIndex] = B;
+  }
+
+  Block *getGraphBlock(COFFSectionIndex SecIndex) const {
+    if (SecIndex <= 0 ||
+        SecIndex >= static_cast<COFFSectionIndex>(GraphSymbols.size()))
+      return nullptr;
+    return GraphBlocks[SecIndex];
+  }
+
+  object::COFFObjectFile::section_iterator_range sections() const {
+    return Obj.sections();
+  }
+
+  /// Traverse all matching relocation records in the given section. The handler
+  /// function Func should be callable with this signature:
+  ///   Error(const object::RelocationRef&,
+  ///         const object::SectionRef&, Section &)
+  ///
+  template <typename RelocHandlerFunction>
+  Error forEachRelocation(const object::SectionRef &RelSec,
+                          RelocHandlerFunction &&Func,
+                          bool ProcessDebugSections = false);
+
+  /// Traverse all matching relocation records in the given section. Convenience
+  /// wrapper to allow passing a member function for the handler.
+  ///
+  template <typename ClassT, typename RelocHandlerMethod>
+  Error forEachRelocation(const object::SectionRef &RelSec, ClassT *Instance,
+                          RelocHandlerMethod &&Method,
+                          bool ProcessDebugSections = false) {
+    return forEachRelocation(
+        RelSec,
+        [Instance, Method](const auto &Rel, const auto &Target, auto &GS) {
+          return (Instance->*Method)(Rel, Target, GS);
+        },
+        ProcessDebugSections);
+  }
+
+private:
+  // Pending comdat symbol export that is initiated by the first symbol of
+  // COMDAT sequence.
+  struct ComdatExportRequest {
+    COFFSymbolIndex SymbolIndex;
+    COFFSectionIndex SectionIndex;
+    jitlink::Linkage Linkage;
+  };
+  Optional<ComdatExportRequest> PendingComdatExport;
+
+  // This represents a pending request to create a weak external symbol with a
+  // name.
+  struct WeakAliasRequest {
+    COFFSymbolIndex Alias;
+    COFFSymbolIndex Target;
+    StringRef SymbolName;
+  };
+  std::vector<WeakAliasRequest> WeakAliasRequests;
+
+  // Per COFF section jitlink symbol set sorted by offset.
+  // Used for calculating implicit size of defined symbols.
+  using SymbolSet = std::set<std::pair<orc::ExecutorAddrDiff, Symbol *>>;
+  std::vector<SymbolSet> SymbolSets;
+
+  Section &getCommonSection();
+
+  Expected<Symbol *> createDefinedSymbol(COFFSymbolIndex SymIndex,
+                                         StringRef SymbolName,
+                                         object::COFFSymbolRef Symbol,
+                                         const object::coff_section *Section);
+  Expected<Symbol *> createCOMDATExportRequest(
+      COFFSymbolIndex SymIndex, object::COFFSymbolRef Symbol,
+      const object::coff_aux_section_definition *Definition);
+  Expected<Symbol *> exportCOMDATSymbol(COFFSymbolIndex SymIndex,
+                                        StringRef SymbolName,
+                                        object::COFFSymbolRef Symbol);
+  Error flushWeakAliasRequests();
+  Error calculateImplicitSizeOfSymbols();
+
+  static uint64_t getSectionAddress(const object::COFFObjectFile &Obj,
+                                    const object::coff_section *Section);
+  static uint64_t getSectionSize(const object::COFFObjectFile &Obj,
+                                 const object::coff_section *Section);
+  static bool isComdatSection(const object::coff_section *Section);
+  static unsigned getPointerSize(const object::COFFObjectFile &Obj);
+  static support::endianness getEndianness(const object::COFFObjectFile &Obj);
+  StringRef getCOFFSectionName(COFFSectionIndex SectionIndex,
+                               const object::coff_section *Sec,
+                               object::COFFSymbolRef Sym);
+
+  const object::COFFObjectFile &Obj;
+  std::unique_ptr<LinkGraph> G;
+
+  Section *CommonSection = nullptr;
+  std::vector<Block *> GraphBlocks;
+  std::vector<Symbol *> GraphSymbols;
+};
+
+template <typename RelocHandlerFunction>
+Error COFFLinkGraphBuilder::forEachRelocation(const object::SectionRef &RelSec,
+                                              RelocHandlerFunction &&Func,
+                                              bool ProcessDebugSections) {
+
+  auto COFFRelSect = Obj.getCOFFSection(RelSec);
+
+  // Target sections have names in valid COFF object files.
+  Expected<StringRef> Name = Obj.getSectionName(COFFRelSect);
+  if (!Name)
+    return Name.takeError();
+  LLVM_DEBUG(dbgs() << "  " << *Name << ":\n");
+
+  // Lookup the link-graph node corresponding to the target section name.
+  auto *BlockToFix = getGraphBlock(RelSec.getIndex() + 1);
+  if (!BlockToFix)
+    return make_error<StringError>(
+        "Referencing a section that wasn't added to the graph: " + *Name,
+        inconvertibleErrorCode());
+
+  // Let the callee process relocation entries one by one.
+  for (const auto &R : RelSec.relocations())
+    if (Error Err = Func(R, RelSec, *BlockToFix))
+      return Err;
+
+  LLVM_DEBUG(dbgs() << "\n");
+  return Error::success();
+}
+
+} // end namespace jitlink
+} // end namespace llvm
+
+#endif // LIB_EXECUTIONENGINE_JITLINK_COFFLINKGRAPHBUILDER_H