--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lld/MachO/MapFile.cpp	Tue Jun 08 06:07:14 2021 +0900
@@ -0,0 +1,159 @@
+//===- MapFile.cpp --------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the -map option. It shows lists in order and
+// hierarchically the outputFile, arch, input files, output sections and
+// symbol:
+//
+// # Path: test
+// # Arch: x86_84
+// # Object files:
+// [  0] linker synthesized
+// [  1] a.o
+// # Sections:
+// # Address  Size      Segment  Section
+// 0x1000005C0  0x0000004C  __TEXT  __text
+// # Symbols:
+// # Address  File  Name
+// 0x1000005C0  [  1] _main
+//
+//===----------------------------------------------------------------------===//
+
+#include "MapFile.h"
+#include "Config.h"
+#include "InputFiles.h"
+#include "InputSection.h"
+#include "OutputSection.h"
+#include "OutputSegment.h"
+#include "Symbols.h"
+#include "Target.h"
+#include "llvm/Support/Parallel.h"
+#include "llvm/Support/TimeProfiler.h"
+
+using namespace llvm;
+using namespace llvm::sys;
+using namespace lld;
+using namespace lld::macho;
+
+using SymbolMapTy = DenseMap<const InputSection *, SmallVector<Defined *, 4>>;
+
+// Returns a map from sections to their symbols.
+static SymbolMapTy getSectionSyms(ArrayRef<Defined *> syms) {
+  SymbolMapTy ret;
+  for (Defined *dr : syms)
+    ret[dr->isec].push_back(dr);
+
+  // Sort symbols by address. We want to print out symbols in the
+  // order in the output file rather than the order they appeared
+  // in the input files.
+  for (auto &it : ret)
+    llvm::stable_sort(it.second, [](Defined *a, Defined *b) {
+      return a->getVA() < b->getVA();
+    });
+  return ret;
+}
+
+// Returns a list of all symbols that we want to print out.
+static std::vector<Defined *> getSymbols() {
+  std::vector<Defined *> v;
+  for (InputFile *file : inputFiles)
+    if (isa<ObjFile>(file))
+      for (Symbol *sym : file->symbols) {
+        if (auto *d = dyn_cast_or_null<Defined>(sym))
+          if (d->isLive() && d->isec && d->getFile() == file) {
+            assert(!d->isec->isCoalescedWeak() &&
+                   "file->symbols should store resolved symbols");
+            v.push_back(d);
+          }
+      }
+  return v;
+}
+
+// Construct a map from symbols to their stringified representations.
+// Demangling symbols (which is what toString() does) is slow, so
+// we do that in batch using parallel-for.
+static DenseMap<Symbol *, std::string>
+getSymbolStrings(ArrayRef<Defined *> syms) {
+  std::vector<std::string> str(syms.size());
+  parallelForEachN(0, syms.size(), [&](size_t i) {
+    raw_string_ostream os(str[i]);
+    os << toString(*syms[i]);
+  });
+
+  DenseMap<Symbol *, std::string> ret;
+  for (size_t i = 0, e = syms.size(); i < e; ++i)
+    ret[syms[i]] = std::move(str[i]);
+  return ret;
+}
+
+void macho::writeMapFile() {
+  if (config->mapFile.empty())
+    return;
+
+  TimeTraceScope timeScope("Write map file");
+
+  // Open a map file for writing.
+  std::error_code ec;
+  raw_fd_ostream os(config->mapFile, ec, sys::fs::OF_None);
+  if (ec) {
+    error("cannot open " + config->mapFile + ": " + ec.message());
+    return;
+  }
+
+  // Dump output path.
+  os << format("# Path: %s\n", config->outputFile.str().c_str());
+
+  // Dump output architecture.
+  os << format("# Arch: %s\n",
+               getArchitectureName(config->arch()).str().c_str());
+
+  // Dump table of object files.
+  os << "# Object files:\n";
+  os << format("[%3u] %s\n", 0, (const char *)"linker synthesized");
+  uint32_t fileIndex = 1;
+  DenseMap<lld::macho::InputFile *, uint32_t> readerToFileOrdinal;
+  for (InputFile *file : inputFiles) {
+    if (isa<ObjFile>(file)) {
+      os << format("[%3u] %s\n", fileIndex, file->getName().str().c_str());
+      readerToFileOrdinal[file] = fileIndex++;
+    }
+  }
+
+  // Collect symbol info that we want to print out.
+  std::vector<Defined *> syms = getSymbols();
+  SymbolMapTy sectionSyms = getSectionSyms(syms);
+  DenseMap<Symbol *, std::string> symStr = getSymbolStrings(syms);
+
+  // Dump table of sections
+  os << "# Sections:\n";
+  os << "# Address\tSize    \tSegment\tSection\n";
+  for (OutputSegment *seg : outputSegments)
+    for (OutputSection *osec : seg->getSections()) {
+      if (osec->isHidden())
+        continue;
+
+      os << format("0x%08llX\t0x%08llX\t%s\t%s\n", osec->addr, osec->getSize(),
+                   seg->name.str().c_str(), osec->name.str().c_str());
+    }
+
+  // Dump table of symbols
+  os << "# Symbols:\n";
+  os << "# Address\t    File  Name\n";
+  for (InputSection *isec : inputSections) {
+    auto symsIt = sectionSyms.find(isec);
+    assert(!isec->shouldOmitFromOutput() || (symsIt == sectionSyms.end()));
+    if (symsIt == sectionSyms.end())
+      continue;
+    for (Symbol *sym : symsIt->second) {
+      os << format("0x%08llX\t[%3u] %s\n", sym->getVA(),
+                   readerToFileOrdinal[sym->getFile()], symStr[sym].c_str());
+    }
+  }
+
+  // TODO: when we implement -dead_strip, we should dump dead stripped symbols
+}