llvm5-0008-Fix-printing-policy-for-AST-context-loaded-from-file.patch

From f612539aaee3a46abbbc8fa30d0263d9b49dca86 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Johann=20Kl=C3=A4hn?= <dev@jklaehn.de>
Date: Mon, 10 Jul 2017 12:34:10 +0200
Subject: [PATCH 08/12] Fix printing policy for AST context loaded from file

In ASTUnit::LoadFromASTFile, the context object is set up using default-constructed
LangOptions (which only later get populated).  As the language options are used in the constructor
of PrintingPolicy, this needs to be updated explicitly after the language options are available.
---
 lib/Frontend/ASTUnit.cpp           |  3 ++
 unittests/Frontend/ASTUnitTest.cpp | 87 ++++++++++++++++++++++++++++++++++++++
 unittests/Frontend/CMakeLists.txt  |  1 +
 3 files changed, 91 insertions(+)
 create mode 100644 unittests/Frontend/ASTUnitTest.cpp

diff --git a/tools/clang/lib/Frontend/ASTUnit.cpp b/tools/clang/lib/Frontend/ASTUnit.cpp
index 875f21d69a..bb1ea6c4f8 100644
--- a/tools/clang/lib/Frontend/ASTUnit.cpp
+++ b/tools/clang/lib/Frontend/ASTUnit.cpp
@@ -546,6 +546,9 @@ private:
     // 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(
diff --git a/tools/clang/unittests/Frontend/ASTUnitTest.cpp b/tools/clang/unittests/Frontend/ASTUnitTest.cpp
new file mode 100644
index 0000000000..a7d08a992f
--- /dev/null
+++ b/tools/clang/unittests/Frontend/ASTUnitTest.cpp
@@ -0,0 +1,87 @@
+//===- 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 "llvm/Support/ToolOutputFile.h"
+#include "gtest/gtest.h"
+
+using namespace llvm;
+using namespace clang;
+
+namespace {
+
+TEST(ASTUnit, 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);
+  }
+
+  int FD;
+  llvm::SmallString<256> InputFileName;
+  ASSERT_FALSE(llvm::sys::fs::createTemporaryFile("ast-unit", "cpp", FD, InputFileName));
+  tool_output_file input_file(InputFileName, FD);
+  input_file.os() << "";
+
+  const char* Args[] = {"clang", "-xc++", InputFileName.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";
+
+  FileManager *FileMgr =
+      new FileManager(FileSystemOptions(), vfs::getRealFileSystem());
+  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);
+
+  llvm::SmallString<256> ASTFileName;
+  ASSERT_FALSE(llvm::sys::fs::createTemporaryFile("ast-unit", "ast", FD, ASTFileName));
+  tool_output_file ast_file(ASTFileName, FD);
+  AST->Save(ASTFileName.str());
+
+  EXPECT_TRUE(llvm::sys::fs::exists(ASTFileName));
+
+  std::unique_ptr<ASTUnit> AU = ASTUnit::LoadFromASTFile(
+      ASTFileName.str(), PCHContainerOps->getRawReader(), ASTUnit::LoadEverything, Diags,
+      FileSystemOptions(), /*UseDebugInfo=*/false);
+
+  if (!AU)
+    FAIL() << "failed to load ASTUnit";
+
+  EXPECT_FALSE(AU->getASTContext().getPrintingPolicy().UseVoidForZeroParams);
+}
+
+} // anonymous namespace
diff --git a/tools/clang/unittests/Frontend/CMakeLists.txt b/tools/clang/unittests/Frontend/CMakeLists.txt
index 674f77bd01..4312151c04 100644
--- a/tools/clang/unittests/Frontend/CMakeLists.txt
+++ b/tools/clang/unittests/Frontend/CMakeLists.txt
@@ -3,6 +3,7 @@ set(LLVM_LINK_COMPONENTS
   )
 
 add_clang_unittest(FrontendTests
+  ASTUnitTest.cpp
   FrontendActionTest.cpp
   CodeGenActionTest.cpp
   )
-- 
2.13.0