Index: lib/Frontend/ASTUnit.cpp
===================================================================
--- lib/Frontend/ASTUnit.cpp
+++ lib/Frontend/ASTUnit.cpp
@@ -542,6 +542,9 @@
     // Initialize the ASTContext
     Context->InitBuiltinTypes(*Target);
 
+    // Adjust printing policy based on language options.
+    Context->setPrintingPolicy(PrintingPolicy(LangOpt));
+
     // We didn't have access to the comment options when the ASTContext was
     // constructed, so register them now.
     Context->getCommentCommandTraits().registerCommentOptions(
Index: unittests/Frontend/ASTUnitTest.cpp
===================================================================
--- /dev/null
+++ unittests/Frontend/ASTUnitTest.cpp
@@ -0,0 +1,113 @@
+//===- unittests/Frontend/ASTUnitTest.cpp - ASTUnit tests -----------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include <fstream>
+
+#include "clang/Frontend/ASTUnit.h"
+#include "clang/Frontend/CompilerInstance.h"
+#include "clang/Frontend/CompilerInvocation.h"
+#include "clang/Frontend/PCHContainerOperations.h"
+#include "llvm/Support/FileSystem.h"
+#include "llvm/Support/Path.h"
+#include "gtest/gtest.h"
+
+using namespace llvm;
+using namespace clang;
+
+namespace {
+
+class ASTUnitTest : public ::testing::Test {
+  std::set<std::string> TemporaryFiles;
+  std::string TestDir;
+
+public:
+  void SetUp() override {
+    llvm::SmallString<256> Dir;
+    ASSERT_FALSE(llvm::sys::fs::createUniqueDirectory("astunit-test", Dir));
+    TestDir = Dir.str();
+  }
+
+  void TearDown() override {
+    for (const std::string &Path : TemporaryFiles)
+      llvm::sys::fs::remove(Path);
+    llvm::sys::fs::remove(TestDir);
+  }
+
+  void MarkTemporaryFile(std::string &Filename) {
+    assert(!llvm::sys::path::is_absolute(Filename));
+    llvm::SmallString<256> Path(TestDir);
+    llvm::sys::path::append(Path, Filename);
+    Filename = Path.str();
+    TemporaryFiles.insert(Filename);
+    llvm::sys::fs::create_directories(llvm::sys::path::parent_path(Filename));
+  }
+};
+
+TEST_F(ASTUnitTest, SaveLoadPreservesLangOptionsInPrintingPolicy) {
+  // Check that the printing policy is restored with the correct language
+  // options when loading an ASTUnit from a file.  To this end, an ASTUnit
+  // for a C++ translation unit is set up and written to a temporary file.
+
+  // By default `UseVoidForZeroParams` is true for non-C++ language options,
+  // thus we can check this field after loading the ASTUnit to deduce whether
+  // the correct (C++) language options were used when setting up the printing
+  // policy.
+
+  {
+    PrintingPolicy PolicyWithDefaultLangOpt(LangOptions{});
+    EXPECT_TRUE(PolicyWithDefaultLangOpt.UseVoidForZeroParams);
+  }
+
+  std::string FileName = "empty_file.cpp";
+  MarkTemporaryFile(FileName);
+  std::ofstream OS(FileName);
+  OS << "";
+  ASSERT_TRUE(OS.good());
+
+  const char* Args[] = {"clang", "-xc++", FileName.c_str()};
+
+  IntrusiveRefCntPtr<DiagnosticsEngine> Diags =
+      CompilerInstance::createDiagnostics(new DiagnosticOptions());
+
+  std::shared_ptr<CompilerInvocation> CInvok =
+      createInvocationFromCommandLine(Args, Diags);
+
+  if (!CInvok)
+    FAIL() << "could not create compiler invocation";
+
+  IntrusiveRefCntPtr<vfs::InMemoryFileSystem> VFS(new vfs::InMemoryFileSystem);
+  VFS->addFile(FileName, 0, llvm::MemoryBuffer::getMemBuffer(""));
+  FileManager *FileMgr = new FileManager(FileSystemOptions(), VFS);
+  auto PCHContainerOps = std::make_shared<PCHContainerOperations>();
+
+  std::unique_ptr<ASTUnit> AST = ASTUnit::LoadFromCompilerInvocation(
+      CInvok, PCHContainerOps, Diags, FileMgr);
+
+  if (!AST)
+    FAIL() << "failed to create ASTUnit";
+
+  EXPECT_FALSE(AST->getASTContext().getPrintingPolicy().UseVoidForZeroParams);
+
+  std::string Path = "printing_policy.ast";
+  MarkTemporaryFile(Path);
+  AST->Save(Path);
+
+  EXPECT_TRUE(llvm::sys::fs::exists(Path));
+
+  std::unique_ptr<ASTUnit> AU = ASTUnit::LoadFromASTFile(
+      Path, PCHContainerOps->getRawReader(), ASTUnit::LoadEverything, Diags,
+      FileSystemOptions(), /*UseDebugInfo=*/false);
+
+  if (!AU)
+    FAIL() << "failed to load ASTUnit";
+
+  EXPECT_FALSE(AU->getASTContext().getPrintingPolicy().UseVoidForZeroParams);
+}
+
+} // anonymous namespace
Index: unittests/Frontend/CMakeLists.txt
===================================================================
--- unittests/Frontend/CMakeLists.txt
+++ unittests/Frontend/CMakeLists.txt
@@ -3,6 +3,7 @@
   )
 
 add_clang_unittest(FrontendTests
+  ASTUnitTest.cpp
   FrontendActionTest.cpp
   CodeGenActionTest.cpp
   )