4 files changed, 35 insertions, 1 deletions
diff --git a/lld/COFF/CMakeLists.txt b/lld/COFF/CMakeLists.txt
index e76496bc4db..78dc34eff96 100644
--- a/lld/COFF/CMakeLists.txt
+++ b/lld/COFF/CMakeLists.txt
@@ -12,6 +12,7 @@ add_llvm_library(lldCOFF
   InputFiles.cpp
   MarkLive.cpp
   ModuleDef.cpp
+  PDB.cpp
   SymbolTable.cpp
   Symbols.cpp
   Writer.cpp
diff --git a/lld/COFF/Driver.cpp b/lld/COFF/Driver.cpp
index f4ce04aa914..f528dafd985 100644
--- a/lld/COFF/Driver.cpp
+++ b/lld/COFF/Driver.cpp
@@ -648,7 +648,7 @@ void LinkerDriver::link(llvm::ArrayRef<const char *> ArgsArr) {
 
   // Create a dummy PDB file to satisfy build sytem rules.
   if (auto *Arg = Args.getLastArg(OPT_pdb))
-    touchFile(Arg->getValue());
+    createPDB(Arg->getValue());
 
   // Identify unreferenced COMDAT sections.
   if (Config->DoGC)
diff --git a/lld/COFF/Driver.h b/lld/COFF/Driver.h
index f3439682dc0..e50da20cbb0 100644
--- a/lld/COFF/Driver.h
+++ b/lld/COFF/Driver.h
@@ -164,6 +164,7 @@ std::unique_ptr<MemoryBuffer>
 convertResToCOFF(const std::vector<MemoryBufferRef> &MBs);
 
 void touchFile(StringRef Path);
+void createPDB(StringRef Path);
 
 // Create enum with OPT_xxx values for each option in Options.td
 enum {
diff --git a/lld/COFF/PDB.cpp b/lld/COFF/PDB.cpp
new file mode 100644
index 00000000000..62f9ba4df32
--- /dev/null
+++ b/lld/COFF/PDB.cpp
@@ -0,0 +1,32 @@
+//===- PDB.cpp ------------------------------------------------------------===//
+//
+//                             The LLVM Linker
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "Driver.h"
+#include "Error.h"
+#include "Symbols.h"
+#include "llvm/Support/FileOutputBuffer.h"
+#include <memory>
+
+using namespace llvm;
+
+const int PageSize = 4096;
+const uint8_t Magic[32] = "Microsoft C/C++ MSF 7.00\r\n\032DS\0\0";
+
+void lld::coff::createPDB(StringRef Path) {
+  // Create a file.
+  size_t FileSize = PageSize * 3;
+  ErrorOr<std::unique_ptr<FileOutputBuffer>> BufOrErr =
+      FileOutputBuffer::create(Path, FileSize);
+  error(BufOrErr, Twine("failed to open ") + Path);
+  std::unique_ptr<FileOutputBuffer> Buf = std::move(*BufOrErr);
+
+  // Write the file magic.
+  uint8_t *P = Buf->getBufferStart();
+  memcpy(P, Magic, sizeof(Magic));
+}