Implement -Map.

The format is not exactly the same as the one in bfd since bfd always
follows a linker script and prints it along.

llvm-svn: 291958
diff --git a/lld/ELF/MapFile.cpp b/lld/ELF/MapFile.cpp
new file mode 100644
index 0000000..89d7f41
--- /dev/null
+++ b/lld/ELF/MapFile.cpp
@@ -0,0 +1,135 @@
+//===- MapFile.cpp --------------------------------------------------------===//
+//
+//                             The LLVM Linker
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the -Map option. It shows lists in order and
+// hierarchically the output sections, input sections, input files and
+// symbol:
+//
+// Address  Size     Align Out     In      File    Symbol
+// =================================================================
+// 00201000 00000015     4 .text
+// 00201000 0000000e     4         .text
+// 00201000 0000000e     4                 test.o
+// 0020100e 00000000     0                         local
+// 00201005 00000000     0                         f(int)
+//
+//===----------------------------------------------------------------------===//
+
+#include "MapFile.h"
+#include "InputFiles.h"
+#include "Strings.h"
+
+#include "llvm/Support/FileUtilities.h"
+
+using namespace llvm;
+using namespace llvm::object;
+
+using namespace lld;
+using namespace lld::elf;
+
+static void writeOutSecLine(raw_fd_ostream &OS, int Width, uint64_t Address,
+                            uint64_t Size, uint64_t Align, StringRef Name) {
+  OS << format_hex_no_prefix(Address, Width) << ' '
+     << format_hex_no_prefix(Size, Width) << ' ' << format("%5x ", Align)
+     << left_justify(Name, 7);
+}
+
+static void writeInSecLine(raw_fd_ostream &OS, int Width, uint64_t Address,
+                           uint64_t Size, uint64_t Align, StringRef Name) {
+  // Pass an empty name to align the text to the correct column.
+  writeOutSecLine(OS, Width, Address, Size, Align, "");
+  OS << ' ' << left_justify(Name, 7);
+}
+
+static void writeFileLine(raw_fd_ostream &OS, int Width, uint64_t Address,
+                          uint64_t Size, uint64_t Align, StringRef Name) {
+  // Pass an empty name to align the text to the correct column.
+  writeInSecLine(OS, Width, Address, Size, Align, "");
+  OS << ' ' << left_justify(Name, 7);
+}
+
+static void writeSymbolLine(raw_fd_ostream &OS, int Width, uint64_t Address,
+                            uint64_t Size, StringRef Name) {
+  // Pass an empty name to align the text to the correct column.
+  writeFileLine(OS, Width, Address, Size, 0, "");
+  OS << ' ' << left_justify(Name, 7);
+}
+
+template <class ELFT>
+static void writeMapFile2(int FD,
+                          ArrayRef<OutputSectionBase *> OutputSections) {
+  typedef typename ELFT::uint uintX_t;
+  raw_fd_ostream OS(FD, true);
+  int Width = ELFT::Is64Bits ? 16 : 8;
+  OS << left_justify("Address", Width) << ' ' << left_justify("Size", Width)
+     << ' ' << left_justify("Align", 5) << ' ' << left_justify("Out", 7) << ' '
+     << left_justify("In", 7) << ' ' << left_justify("File", 7) << " Symbol\n";
+  for (OutputSectionBase *Sec : OutputSections) {
+    uintX_t VA = Sec->Addr;
+    writeOutSecLine(OS, Width, VA, Sec->Size, Sec->Addralign, Sec->getName());
+    OS << '\n';
+    StringRef PrevName = "";
+    Sec->forEachInputSection([&](InputSectionData *S) {
+      const auto *IS = dyn_cast<InputSection<ELFT>>(S);
+      if (!IS)
+        return;
+      StringRef Name = IS->Name;
+      if (Name != PrevName) {
+        writeInSecLine(OS, Width, VA + IS->OutSecOff, IS->getSize(),
+                       IS->Alignment, Name);
+        OS << '\n';
+        PrevName = Name;
+      }
+      elf::ObjectFile<ELFT> *File = IS->getFile();
+      if (!File)
+        return;
+      writeFileLine(OS, Width, VA + IS->OutSecOff, IS->getSize(), IS->Alignment,
+                    toString(File));
+      OS << '\n';
+      ArrayRef<SymbolBody *> Syms = File->getSymbols();
+      for (SymbolBody *Sym : Syms) {
+        auto *DR = dyn_cast<DefinedRegular<ELFT>>(Sym);
+        if (!DR)
+          continue;
+        if (DR->Section != IS)
+          continue;
+        if (DR->isSection())
+          continue;
+        writeSymbolLine(OS, Width, Sym->getVA<ELFT>(), Sym->getSize<ELFT>(),
+                        toString(*Sym));
+        OS << '\n';
+      }
+    });
+  }
+}
+
+template <class ELFT>
+void elf::writeMapFile(ArrayRef<OutputSectionBase *> OutputSections) {
+  StringRef MapFile = Config->MapFile;
+  if (MapFile.empty())
+    return;
+
+  // Create new file in same directory but with random name.
+  SmallString<128> TempPath;
+  int FD;
+  std::error_code EC =
+      sys::fs::createUniqueFile(Twine(MapFile) + ".tmp%%%%%%%", FD, TempPath);
+  if (EC)
+    fatal(EC.message());
+  FileRemover RAII(TempPath);
+  writeMapFile2<ELFT>(FD, OutputSections);
+  EC = sys::fs::rename(TempPath, MapFile);
+  if (EC)
+    fatal(EC.message());
+}
+
+template void elf::writeMapFile<ELF32LE>(ArrayRef<OutputSectionBase *>);
+template void elf::writeMapFile<ELF32BE>(ArrayRef<OutputSectionBase *>);
+template void elf::writeMapFile<ELF64LE>(ArrayRef<OutputSectionBase *>);
+template void elf::writeMapFile<ELF64BE>(ArrayRef<OutputSectionBase *>);