--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lld/COFF/Writer.h	Thu Feb 13 15:10:13 2020 +0900
@@ -0,0 +1,85 @@
+//===- Writer.h -------------------------------------------------*- 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLD_COFF_WRITER_H
+#define LLD_COFF_WRITER_H
+
+#include "Chunks.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/Object/COFF.h"
+#include <chrono>
+#include <cstdint>
+#include <vector>
+
+namespace lld {
+namespace coff {
+static const int pageSize = 4096;
+
+void writeResult();
+
+class PartialSection {
+public:
+  PartialSection(StringRef n, uint32_t chars)
+      : name(n), characteristics(chars) {}
+  StringRef name;
+  unsigned characteristics;
+  std::vector<Chunk *> chunks;
+};
+
+// OutputSection represents a section in an output file. It's a
+// container of chunks. OutputSection and Chunk are 1:N relationship.
+// Chunks cannot belong to more than one OutputSections. The writer
+// creates multiple OutputSections and assign them unique,
+// non-overlapping file offsets and RVAs.
+class OutputSection {
+public:
+  OutputSection(llvm::StringRef n, uint32_t chars) : name(n) {
+    header.Characteristics = chars;
+  }
+  void addChunk(Chunk *c);
+  void insertChunkAtStart(Chunk *c);
+  void merge(OutputSection *other);
+  void setPermissions(uint32_t c);
+  uint64_t getRVA() { return header.VirtualAddress; }
+  uint64_t getFileOff() { return header.PointerToRawData; }
+  void writeHeaderTo(uint8_t *buf);
+  void addContributingPartialSection(PartialSection *sec);
+
+  // Returns the size of this section in an executable memory image.
+  // This may be smaller than the raw size (the raw size is multiple
+  // of disk sector size, so there may be padding at end), or may be
+  // larger (if that's the case, the loader reserves spaces after end
+  // of raw data).
+  uint64_t getVirtualSize() { return header.VirtualSize; }
+
+  // Returns the size of the section in the output file.
+  uint64_t getRawSize() { return header.SizeOfRawData; }
+
+  // Set offset into the string table storing this section name.
+  // Used only when the name is longer than 8 bytes.
+  void setStringTableOff(uint32_t v) { stringTableOff = v; }
+
+  // N.B. The section index is one based.
+  uint32_t sectionIndex = 0;
+
+  llvm::StringRef name;
+  llvm::object::coff_section header = {};
+
+  std::vector<Chunk *> chunks;
+  std::vector<Chunk *> origChunks;
+
+  std::vector<PartialSection *> contribSections;
+
+private:
+  uint32_t stringTableOff = 0;
+};
+
+} // namespace coff
+} // namespace lld
+
+#endif