Import LLVM 10.0.0 release including clang, lld and lldb.

ok hackroom
tested by plenty

9 files changed, 1100 insertions, 0 deletions

diff --git a/gnu/llvm/clang/unittests/Frontend/ASTUnitTest.cpp b/gnu/llvm/clang/unittests/Frontend/ASTUnitTest.cpp
new file mode 100644
index 00000000000..5cb20872f0b
--- /dev/null
+++ b/gnu/llvm/clang/unittests/Frontend/ASTUnitTest.cpp
@@ -0,0 +1,113 @@
+//===- unittests/Frontend/ASTUnitTest.cpp - ASTUnit tests -----------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#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 {
+
+class ASTUnitTest : public ::testing::Test {
+protected:
+  int FD;
+  llvm::SmallString<256> InputFileName;
+  std::unique_ptr<ToolOutputFile> input_file;
+  IntrusiveRefCntPtr<DiagnosticsEngine> Diags;
+  std::shared_ptr<CompilerInvocation> CInvok;
+  std::shared_ptr<PCHContainerOperations> PCHContainerOps;
+
+  std::unique_ptr<ASTUnit> createASTUnit(bool isVolatile) {
+    EXPECT_FALSE(llvm::sys::fs::createTemporaryFile("ast-unit", "cpp", FD,
+                                                    InputFileName));
+    input_file = std::make_unique<ToolOutputFile>(InputFileName, FD);
+    input_file->os() << "";
+
+    const char *Args[] = {"clang", "-xc++", InputFileName.c_str()};
+
+    Diags = CompilerInstance::createDiagnostics(new DiagnosticOptions());
+
+    CInvok = createInvocationFromCommandLine(Args, Diags);
+
+    if (!CInvok)
+      return nullptr;
+
+    FileManager *FileMgr =
+        new FileManager(FileSystemOptions(), vfs::getRealFileSystem());
+    PCHContainerOps = std::make_shared<PCHContainerOperations>();
+
+    return ASTUnit::LoadFromCompilerInvocation(
+        CInvok, PCHContainerOps, Diags, FileMgr, false, CaptureDiagsKind::None,
+        0, TU_Complete, false, false, isVolatile);
+  }
+};
+
+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::unique_ptr<ASTUnit> AST = createASTUnit(false);
+
+  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));
+  ToolOutputFile 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);
+}
+
+TEST_F(ASTUnitTest, GetBufferForFileMemoryMapping) {
+  std::unique_ptr<ASTUnit> AST = createASTUnit(true);
+
+  if (!AST)
+    FAIL() << "failed to create ASTUnit";
+
+  std::unique_ptr<llvm::MemoryBuffer> memoryBuffer =
+      AST->getBufferForFile(InputFileName);
+
+  EXPECT_NE(memoryBuffer->getBufferKind(),
+            llvm::MemoryBuffer::MemoryBuffer_MMap);
+}
+
+} // anonymous namespace
diff --git a/gnu/llvm/clang/unittests/Frontend/CMakeLists.txt b/gnu/llvm/clang/unittests/Frontend/CMakeLists.txt
new file mode 100644
index 00000000000..cde19e91061
--- /dev/null
+++ b/gnu/llvm/clang/unittests/Frontend/CMakeLists.txt
@@ -0,0 +1,25 @@
+set(LLVM_LINK_COMPONENTS
+  Support
+  )
+
+add_clang_unittest(FrontendTests
+  ASTUnitTest.cpp
+  CompilerInstanceTest.cpp
+  FixedPointString.cpp
+  FrontendActionTest.cpp
+  CodeGenActionTest.cpp
+  ParsedSourceLocationTest.cpp
+  PCHPreambleTest.cpp
+  OutputStreamTest.cpp
+  )
+clang_target_link_libraries(FrontendTests
+  PRIVATE
+  clangAST
+  clangBasic
+  clangFrontend
+  clangLex
+  clangSema
+  clangCodeGen
+  clangFrontendTool
+  clangSerialization
+  )
diff --git a/gnu/llvm/clang/unittests/Frontend/CodeGenActionTest.cpp b/gnu/llvm/clang/unittests/Frontend/CodeGenActionTest.cpp
new file mode 100644
index 00000000000..455ec705f88
--- /dev/null
+++ b/gnu/llvm/clang/unittests/Frontend/CodeGenActionTest.cpp
@@ -0,0 +1,62 @@
+//===- unittests/Frontend/CodeGenActionTest.cpp --- FrontendAction tests --===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// Unit tests for CodeGenAction.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/CodeGen/CodeGenAction.h"
+#include "clang/Basic/LangStandard.h"
+#include "clang/CodeGen/BackendUtil.h"
+#include "clang/Frontend/CompilerInstance.h"
+#include "clang/Lex/PreprocessorOptions.h"
+#include "gtest/gtest.h"
+
+using namespace llvm;
+using namespace clang;
+using namespace clang::frontend;
+
+namespace {
+
+
+class NullCodeGenAction : public CodeGenAction {
+public:
+  NullCodeGenAction(llvm::LLVMContext *_VMContext = nullptr)
+    : CodeGenAction(Backend_EmitMCNull, _VMContext) {}
+
+  // The action does not call methods of ATContext.
+  void ExecuteAction() override {
+    CompilerInstance &CI = getCompilerInstance();
+    if (!CI.hasPreprocessor())
+      return;
+    if (!CI.hasSema())
+      CI.createSema(getTranslationUnitKind(), nullptr);
+  }
+};
+
+
+TEST(CodeGenTest, TestNullCodeGen) {
+  auto Invocation = std::make_shared<CompilerInvocation>();
+  Invocation->getPreprocessorOpts().addRemappedFile(
+      "test.cc",
+      MemoryBuffer::getMemBuffer("").release());
+  Invocation->getFrontendOpts().Inputs.push_back(
+      FrontendInputFile("test.cc", Language::CXX));
+  Invocation->getFrontendOpts().ProgramAction = EmitLLVM;
+  Invocation->getTargetOpts().Triple = "i386-unknown-linux-gnu";
+  CompilerInstance Compiler;
+  Compiler.setInvocation(std::move(Invocation));
+  Compiler.createDiagnostics();
+  EXPECT_TRUE(Compiler.hasDiagnostics());
+
+  std::unique_ptr<FrontendAction> Act(new NullCodeGenAction);
+  bool Success = Compiler.ExecuteAction(*Act);
+  EXPECT_TRUE(Success);
+}
+
+}
diff --git a/gnu/llvm/clang/unittests/Frontend/CompilerInstanceTest.cpp b/gnu/llvm/clang/unittests/Frontend/CompilerInstanceTest.cpp
new file mode 100644
index 00000000000..d2377d07406
--- /dev/null
+++ b/gnu/llvm/clang/unittests/Frontend/CompilerInstanceTest.cpp
@@ -0,0 +1,94 @@
+//===- unittests/Frontend/CompilerInstanceTest.cpp - CI tests -------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Frontend/CompilerInstance.h"
+#include "clang/Frontend/CompilerInvocation.h"
+#include "clang/Frontend/TextDiagnosticPrinter.h"
+#include "llvm/Support/FileSystem.h"
+#include "llvm/Support/Format.h"
+#include "llvm/Support/ToolOutputFile.h"
+#include "gtest/gtest.h"
+
+using namespace llvm;
+using namespace clang;
+
+namespace {
+
+TEST(CompilerInstance, DefaultVFSOverlayFromInvocation) {
+  // Create a temporary VFS overlay yaml file.
+  int FD;
+  SmallString<256> FileName;
+  ASSERT_FALSE(sys::fs::createTemporaryFile("vfs", "yaml", FD, FileName));
+  ToolOutputFile File(FileName, FD);
+
+  SmallString<256> CurrentPath;
+  sys::fs::current_path(CurrentPath);
+  sys::fs::make_absolute(CurrentPath, FileName);
+
+  // Mount the VFS file itself on the path 'virtual.file'. Makes this test
+  // a bit shorter than creating a new dummy file just for this purpose.
+  const std::string CurrentPathStr = CurrentPath.str();
+  const std::string FileNameStr = FileName.str();
+  const char *VFSYaml = "{ 'version': 0, 'roots': [\n"
+                        "  { 'name': '%s',\n"
+                        "    'type': 'directory',\n"
+                        "    'contents': [\n"
+                        "      { 'name': 'vfs-virtual.file', 'type': 'file',\n"
+                        "        'external-contents': '%s'\n"
+                        "      }\n"
+                        "    ]\n"
+                        "  }\n"
+                        "]}\n";
+  File.os() << format(VFSYaml, CurrentPathStr.c_str(), FileName.c_str());
+  File.os().flush();
+
+  // Create a CompilerInvocation that uses this overlay file.
+  const std::string VFSArg = "-ivfsoverlay" + FileNameStr;
+  const char *Args[] = {"clang", VFSArg.c_str(), "-xc++", "-"};
+
+  IntrusiveRefCntPtr<DiagnosticsEngine> Diags =
+      CompilerInstance::createDiagnostics(new DiagnosticOptions());
+
+  std::shared_ptr<CompilerInvocation> CInvok =
+      createInvocationFromCommandLine(Args, Diags);
+
+  if (!CInvok)
+    FAIL() << "could not create compiler invocation";
+  // Create a minimal CompilerInstance which should use the VFS we specified
+  // in the CompilerInvocation (as we don't explicitly set our own).
+  CompilerInstance Instance;
+  Instance.setDiagnostics(Diags.get());
+  Instance.setInvocation(CInvok);
+  Instance.createFileManager();
+
+  // Check if the virtual file exists which means that our VFS is used by the
+  // CompilerInstance.
+  ASSERT_TRUE(Instance.getFileManager().getFile("vfs-virtual.file"));
+}
+
+TEST(CompilerInstance, AllowDiagnosticLogWithUnownedDiagnosticConsumer) {
+  auto DiagOpts = new DiagnosticOptions();
+  // Tell the diagnostics engine to emit the diagnostic log to STDERR. This
+  // ensures that a chained diagnostic consumer is created so that the test can
+  // exercise the unowned diagnostic consumer in a chained consumer.
+  DiagOpts->DiagnosticLogFile = "-";
+
+  // Create the diagnostic engine with unowned consumer.
+  std::string DiagnosticOutput;
+  llvm::raw_string_ostream DiagnosticsOS(DiagnosticOutput);
+  auto DiagPrinter = std::make_unique<TextDiagnosticPrinter>(
+      DiagnosticsOS, new DiagnosticOptions());
+  CompilerInstance Instance;
+  IntrusiveRefCntPtr<DiagnosticsEngine> Diags = Instance.createDiagnostics(
+      DiagOpts, DiagPrinter.get(), /*ShouldOwnClient=*/false);
+
+  Diags->Report(diag::err_expected) << "no crash";
+  ASSERT_EQ(DiagnosticsOS.str(), "error: expected no crash\n");
+}
+
+} // anonymous namespace
diff --git a/gnu/llvm/clang/unittests/Frontend/FixedPointString.cpp b/gnu/llvm/clang/unittests/Frontend/FixedPointString.cpp
new file mode 100644
index 00000000000..755efd7fcaa
--- /dev/null
+++ b/gnu/llvm/clang/unittests/Frontend/FixedPointString.cpp
@@ -0,0 +1,107 @@
+#include "clang/AST/Type.h"
+#include "llvm/ADT/APSInt.h"
+#include "llvm/ADT/SmallString.h"
+#include "gtest/gtest.h"
+
+using clang::FixedPointValueToString;
+using llvm::APSInt;
+using llvm::SmallString;
+
+namespace {
+
+TEST(FixedPointString, DifferentTypes) {
+  SmallString<64> S;
+  FixedPointValueToString(S, APSInt::get(320), 7);
+  ASSERT_STREQ(S.c_str(), "2.5");
+
+  S.clear();
+  FixedPointValueToString(S, APSInt::get(0), 7);
+  ASSERT_STREQ(S.c_str(), "0.0");
+
+  // signed short _Accum
+  S.clear();
+  FixedPointValueToString(S, APSInt::getMaxValue(16, /*Unsigned=*/false), 7);
+  ASSERT_STREQ(S.c_str(), "255.9921875");
+
+  // signed _Accum
+  S.clear();
+  FixedPointValueToString(S, APSInt::getMaxValue(32, /*Unsigned=*/false), 15);
+  ASSERT_STREQ(S.c_str(), "65535.999969482421875");
+
+  // signed long _Accum
+  S.clear();
+  FixedPointValueToString(S, APSInt::getMaxValue(64, /*Unsigned=*/false), 31);
+  ASSERT_STREQ(S.c_str(), "4294967295.9999999995343387126922607421875");
+
+  // unsigned short _Accum
+  S.clear();
+  FixedPointValueToString(S, APSInt::getMaxValue(16, /*Unsigned=*/true), 8);
+  ASSERT_STREQ(S.c_str(), "255.99609375");
+
+  // unsigned _Accum
+  S.clear();
+  FixedPointValueToString(S, APSInt::getMaxValue(32, /*Unsigned=*/true), 16);
+  ASSERT_STREQ(S.c_str(), "65535.9999847412109375");
+
+  // unsigned long _Accum
+  S.clear();
+  FixedPointValueToString(S, APSInt::getMaxValue(64, /*Unsigned=*/true), 32);
+  ASSERT_STREQ(S.c_str(), "4294967295.99999999976716935634613037109375");
+
+  // signed short _Fract
+  S.clear();
+  FixedPointValueToString(S, APSInt::getMaxValue(8, /*Unsigned=*/false), 7);
+  ASSERT_STREQ(S.c_str(), "0.9921875");
+
+  // signed _Fract
+  S.clear();
+  FixedPointValueToString(S, APSInt::getMaxValue(16, /*Unsigned=*/false), 15);
+  ASSERT_STREQ(S.c_str(), "0.999969482421875");
+
+  // signed long _Fract
+  S.clear();
+  FixedPointValueToString(S, APSInt::getMaxValue(32, /*Unsigned=*/false), 31);
+  ASSERT_STREQ(S.c_str(), "0.9999999995343387126922607421875");
+
+  // unsigned short _Fract
+  S.clear();
+  FixedPointValueToString(S, APSInt::getMaxValue(8, /*Unsigned=*/true), 8);
+  ASSERT_STREQ(S.c_str(), "0.99609375");
+
+  // unsigned _Fract
+  S.clear();
+  FixedPointValueToString(S, APSInt::getMaxValue(16, /*Unsigned=*/true), 16);
+  ASSERT_STREQ(S.c_str(), "0.9999847412109375");
+
+  // unsigned long _Fract
+  S.clear();
+  FixedPointValueToString(S, APSInt::getMaxValue(32, /*Unsigned=*/true), 32);
+  ASSERT_STREQ(S.c_str(), "0.99999999976716935634613037109375");
+}
+
+TEST(FixedPointString, Negative) {
+  SmallString<64> S;
+  FixedPointValueToString(S, APSInt::get(-320), 7);
+  ASSERT_STREQ(S.c_str(), "-2.5");
+
+  S.clear();
+  FixedPointValueToString(S, APSInt::get(-64), 7);
+  ASSERT_STREQ(S.c_str(), "-0.5");
+
+  // signed short _Accum
+  S.clear();
+  FixedPointValueToString(S, APSInt::getMinValue(16, /*Unsigned=*/false), 7);
+  ASSERT_STREQ(S.c_str(), "-256.0");
+
+  // signed _Accum
+  S.clear();
+  FixedPointValueToString(S, APSInt::getMinValue(32, /*Unsigned=*/false), 15);
+  ASSERT_STREQ(S.c_str(), "-65536.0");
+
+  // signed long _Accum
+  S.clear();
+  FixedPointValueToString(S, APSInt::getMinValue(64, /*Unsigned=*/false), 31);
+  ASSERT_STREQ(S.c_str(), "-4294967296.0");
+}
+
+} // namespace
diff --git a/gnu/llvm/clang/unittests/Frontend/FrontendActionTest.cpp b/gnu/llvm/clang/unittests/Frontend/FrontendActionTest.cpp
new file mode 100644
index 00000000000..95be040ddf1
--- /dev/null
+++ b/gnu/llvm/clang/unittests/Frontend/FrontendActionTest.cpp
@@ -0,0 +1,295 @@
+//===- unittests/Frontend/FrontendActionTest.cpp - FrontendAction tests ---===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Frontend/FrontendAction.h"
+#include "clang/AST/ASTConsumer.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/AST/RecursiveASTVisitor.h"
+#include "clang/Basic/LangStandard.h"
+#include "clang/Frontend/CompilerInstance.h"
+#include "clang/Frontend/CompilerInvocation.h"
+#include "clang/Frontend/FrontendActions.h"
+#include "clang/Lex/Preprocessor.h"
+#include "clang/Lex/PreprocessorOptions.h"
+#include "clang/Sema/Sema.h"
+#include "clang/Serialization/InMemoryModuleCache.h"
+#include "llvm/ADT/Triple.h"
+#include "llvm/Support/MemoryBuffer.h"
+#include "llvm/Support/ToolOutputFile.h"
+#include "gtest/gtest.h"
+
+using namespace llvm;
+using namespace clang;
+
+namespace {
+
+class TestASTFrontendAction : public ASTFrontendAction {
+public:
+  TestASTFrontendAction(bool enableIncrementalProcessing = false,
+                        bool actOnEndOfTranslationUnit = false)
+    : EnableIncrementalProcessing(enableIncrementalProcessing),
+      ActOnEndOfTranslationUnit(actOnEndOfTranslationUnit) { }
+
+  bool EnableIncrementalProcessing;
+  bool ActOnEndOfTranslationUnit;
+  std::vector<std::string> decl_names;
+
+  bool BeginSourceFileAction(CompilerInstance &ci) override {
+    if (EnableIncrementalProcessing)
+      ci.getPreprocessor().enableIncrementalProcessing();
+
+    return ASTFrontendAction::BeginSourceFileAction(ci);
+  }
+
+  std::unique_ptr<ASTConsumer> CreateASTConsumer(CompilerInstance &CI,
+                                                 StringRef InFile) override {
+    return std::make_unique<Visitor>(CI, ActOnEndOfTranslationUnit,
+                                      decl_names);
+  }
+
+private:
+  class Visitor : public ASTConsumer, public RecursiveASTVisitor<Visitor> {
+  public:
+    Visitor(CompilerInstance &CI, bool ActOnEndOfTranslationUnit,
+            std::vector<std::string> &decl_names) :
+      CI(CI), ActOnEndOfTranslationUnit(ActOnEndOfTranslationUnit),
+      decl_names_(decl_names) {}
+
+    void HandleTranslationUnit(ASTContext &context) override {
+      if (ActOnEndOfTranslationUnit) {
+        CI.getSema().ActOnEndOfTranslationUnit();
+      }
+      TraverseDecl(context.getTranslationUnitDecl());
+    }
+
+    virtual bool VisitNamedDecl(NamedDecl *Decl) {
+      decl_names_.push_back(Decl->getQualifiedNameAsString());
+      return true;
+    }
+
+  private:
+    CompilerInstance &CI;
+    bool ActOnEndOfTranslationUnit;
+    std::vector<std::string> &decl_names_;
+  };
+};
+
+TEST(ASTFrontendAction, Sanity) {
+  auto invocation = std::make_shared<CompilerInvocation>();
+  invocation->getPreprocessorOpts().addRemappedFile(
+      "test.cc",
+      MemoryBuffer::getMemBuffer("int main() { float x; }").release());
+  invocation->getFrontendOpts().Inputs.push_back(
+      FrontendInputFile("test.cc", Language::CXX));
+  invocation->getFrontendOpts().ProgramAction = frontend::ParseSyntaxOnly;
+  invocation->getTargetOpts().Triple = "i386-unknown-linux-gnu";
+  CompilerInstance compiler;
+  compiler.setInvocation(std::move(invocation));
+  compiler.createDiagnostics();
+
+  TestASTFrontendAction test_action;
+  ASSERT_TRUE(compiler.ExecuteAction(test_action));
+  ASSERT_EQ(2U, test_action.decl_names.size());
+  EXPECT_EQ("main", test_action.decl_names[0]);
+  EXPECT_EQ("x", test_action.decl_names[1]);
+}
+
+TEST(ASTFrontendAction, IncrementalParsing) {
+  auto invocation = std::make_shared<CompilerInvocation>();
+  invocation->getPreprocessorOpts().addRemappedFile(
+      "test.cc",
+      MemoryBuffer::getMemBuffer("int main() { float x; }").release());
+  invocation->getFrontendOpts().Inputs.push_back(
+      FrontendInputFile("test.cc", Language::CXX));
+  invocation->getFrontendOpts().ProgramAction = frontend::ParseSyntaxOnly;
+  invocation->getTargetOpts().Triple = "i386-unknown-linux-gnu";
+  CompilerInstance compiler;
+  compiler.setInvocation(std::move(invocation));
+  compiler.createDiagnostics();
+
+  TestASTFrontendAction test_action(/*enableIncrementalProcessing=*/true);
+  ASSERT_TRUE(compiler.ExecuteAction(test_action));
+  ASSERT_EQ(2U, test_action.decl_names.size());
+  EXPECT_EQ("main", test_action.decl_names[0]);
+  EXPECT_EQ("x", test_action.decl_names[1]);
+}
+
+TEST(ASTFrontendAction, LateTemplateIncrementalParsing) {
+  auto invocation = std::make_shared<CompilerInvocation>();
+  invocation->getLangOpts()->CPlusPlus = true;
+  invocation->getLangOpts()->DelayedTemplateParsing = true;
+  invocation->getPreprocessorOpts().addRemappedFile(
+    "test.cc", MemoryBuffer::getMemBuffer(
+      "template<typename T> struct A { A(T); T data; };\n"
+      "template<typename T> struct B: public A<T> {\n"
+      "  B();\n"
+      "  B(B const& b): A<T>(b.data) {}\n"
+      "};\n"
+      "B<char> c() { return B<char>(); }\n").release());
+  invocation->getFrontendOpts().Inputs.push_back(
+      FrontendInputFile("test.cc", Language::CXX));
+  invocation->getFrontendOpts().ProgramAction = frontend::ParseSyntaxOnly;
+  invocation->getTargetOpts().Triple = "i386-unknown-linux-gnu";
+  CompilerInstance compiler;
+  compiler.setInvocation(std::move(invocation));
+  compiler.createDiagnostics();
+
+  TestASTFrontendAction test_action(/*enableIncrementalProcessing=*/true,
+                                    /*actOnEndOfTranslationUnit=*/true);
+  ASSERT_TRUE(compiler.ExecuteAction(test_action));
+  ASSERT_EQ(13U, test_action.decl_names.size());
+  EXPECT_EQ("A", test_action.decl_names[0]);
+  EXPECT_EQ("c", test_action.decl_names[12]);
+}
+
+struct TestPPCallbacks : public PPCallbacks {
+  TestPPCallbacks() : SeenEnd(false) {}
+
+  void EndOfMainFile() override { SeenEnd = true; }
+
+  bool SeenEnd;
+};
+
+class TestPPCallbacksFrontendAction : public PreprocessorFrontendAction {
+  TestPPCallbacks *Callbacks;
+
+public:
+  TestPPCallbacksFrontendAction(TestPPCallbacks *C)
+      : Callbacks(C), SeenEnd(false) {}
+
+  void ExecuteAction() override {
+    Preprocessor &PP = getCompilerInstance().getPreprocessor();
+    PP.addPPCallbacks(std::unique_ptr<TestPPCallbacks>(Callbacks));
+    PP.EnterMainSourceFile();
+  }
+  void EndSourceFileAction() override { SeenEnd = Callbacks->SeenEnd; }
+
+  bool SeenEnd;
+};
+
+TEST(PreprocessorFrontendAction, EndSourceFile) {
+  auto Invocation = std::make_shared<CompilerInvocation>();
+  Invocation->getPreprocessorOpts().addRemappedFile(
+      "test.cc",
+      MemoryBuffer::getMemBuffer("int main() { float x; }").release());
+  Invocation->getFrontendOpts().Inputs.push_back(
+      FrontendInputFile("test.cc", Language::CXX));
+  Invocation->getFrontendOpts().ProgramAction = frontend::ParseSyntaxOnly;
+  Invocation->getTargetOpts().Triple = "i386-unknown-linux-gnu";
+  CompilerInstance Compiler;
+  Compiler.setInvocation(std::move(Invocation));
+  Compiler.createDiagnostics();
+
+  TestPPCallbacks *Callbacks = new TestPPCallbacks;
+  TestPPCallbacksFrontendAction TestAction(Callbacks);
+  ASSERT_FALSE(Callbacks->SeenEnd);
+  ASSERT_FALSE(TestAction.SeenEnd);
+  ASSERT_TRUE(Compiler.ExecuteAction(TestAction));
+  // Check that EndOfMainFile was called before EndSourceFileAction.
+  ASSERT_TRUE(TestAction.SeenEnd);
+}
+
+class TypoExternalSemaSource : public ExternalSemaSource {
+  CompilerInstance &CI;
+
+public:
+  TypoExternalSemaSource(CompilerInstance &CI) : CI(CI) {}
+
+  TypoCorrection CorrectTypo(const DeclarationNameInfo &Typo, int LookupKind,
+                             Scope *S, CXXScopeSpec *SS,
+                             CorrectionCandidateCallback &CCC,
+                             DeclContext *MemberContext, bool EnteringContext,
+                             const ObjCObjectPointerType *OPT) override {
+    // Generate a fake typo correction with one attached note.
+    ASTContext &Ctx = CI.getASTContext();
+    TypoCorrection TC(DeclarationName(&Ctx.Idents.get("moo")));
+    unsigned DiagID = Ctx.getDiagnostics().getCustomDiagID(
+        DiagnosticsEngine::Note, "This is a note");
+    TC.addExtraDiagnostic(PartialDiagnostic(DiagID, Ctx.getDiagAllocator()));
+    return TC;
+  }
+};
+
+struct TypoDiagnosticConsumer : public DiagnosticConsumer {
+  void HandleDiagnostic(DiagnosticsEngine::Level DiagLevel,
+                        const Diagnostic &Info) override {
+    // Capture errors and notes. There should be one of each.
+    if (DiagLevel == DiagnosticsEngine::Error) {
+      assert(Error.empty());
+      Info.FormatDiagnostic(Error);
+    } else {
+      assert(Note.empty());
+      Info.FormatDiagnostic(Note);
+    }
+  }
+  SmallString<32> Error;
+  SmallString<32> Note;
+};
+
+TEST(ASTFrontendAction, ExternalSemaSource) {
+  auto Invocation = std::make_shared<CompilerInvocation>();
+  Invocation->getLangOpts()->CPlusPlus = true;
+  Invocation->getPreprocessorOpts().addRemappedFile(
+      "test.cc", MemoryBuffer::getMemBuffer("void fooo();\n"
+                                            "int main() { foo(); }")
+                     .release());
+  Invocation->getFrontendOpts().Inputs.push_back(
+      FrontendInputFile("test.cc", Language::CXX));
+  Invocation->getFrontendOpts().ProgramAction = frontend::ParseSyntaxOnly;
+  Invocation->getTargetOpts().Triple = "i386-unknown-linux-gnu";
+  CompilerInstance Compiler;
+  Compiler.setInvocation(std::move(Invocation));
+  auto *TDC = new TypoDiagnosticConsumer;
+  Compiler.createDiagnostics(TDC, /*ShouldOwnClient=*/true);
+  Compiler.setExternalSemaSource(new TypoExternalSemaSource(Compiler));
+
+  SyntaxOnlyAction TestAction;
+  ASSERT_TRUE(Compiler.ExecuteAction(TestAction));
+  // There should be one error correcting to 'moo' and a note attached to it.
+  EXPECT_EQ("use of undeclared identifier 'foo'; did you mean 'moo'?",
+            TDC->Error.str().str());
+  EXPECT_EQ("This is a note", TDC->Note.str().str());
+}
+
+TEST(GeneratePCHFrontendAction, CacheGeneratedPCH) {
+  // Create a temporary file for writing out the PCH that will be cleaned up.
+  int PCHFD;
+  llvm::SmallString<128> PCHFilename;
+  ASSERT_FALSE(
+      llvm::sys::fs::createTemporaryFile("test.h", "pch", PCHFD, PCHFilename));
+  llvm::ToolOutputFile PCHFile(PCHFilename, PCHFD);
+
+  for (bool ShouldCache : {false, true}) {
+    auto Invocation = std::make_shared<CompilerInvocation>();
+    Invocation->getLangOpts()->CacheGeneratedPCH = ShouldCache;
+    Invocation->getPreprocessorOpts().addRemappedFile(
+        "test.h",
+        MemoryBuffer::getMemBuffer("int foo(void) { return 1; }\n").release());
+    Invocation->getFrontendOpts().Inputs.push_back(
+        FrontendInputFile("test.h", Language::C));
+    Invocation->getFrontendOpts().OutputFile = StringRef(PCHFilename);
+    Invocation->getFrontendOpts().ProgramAction = frontend::GeneratePCH;
+    Invocation->getTargetOpts().Triple = "x86_64-apple-darwin19.0.0";
+    CompilerInstance Compiler;
+    Compiler.setInvocation(std::move(Invocation));
+    Compiler.createDiagnostics();
+
+    GeneratePCHAction TestAction;
+    ASSERT_TRUE(Compiler.ExecuteAction(TestAction));
+
+    // Check whether the PCH was cached.
+    if (ShouldCache)
+      EXPECT_EQ(InMemoryModuleCache::Final,
+                Compiler.getModuleCache().getPCMState(PCHFilename));
+    else
+      EXPECT_EQ(InMemoryModuleCache::Unknown,
+                Compiler.getModuleCache().getPCMState(PCHFilename));
+  }
+}
+
+} // anonymous namespace
diff --git a/gnu/llvm/clang/unittests/Frontend/OutputStreamTest.cpp b/gnu/llvm/clang/unittests/Frontend/OutputStreamTest.cpp
new file mode 100644
index 00000000000..6a867bf053c
--- /dev/null
+++ b/gnu/llvm/clang/unittests/Frontend/OutputStreamTest.cpp
@@ -0,0 +1,103 @@
+//===- unittests/Frontend/OutputStreamTest.cpp --- FrontendAction tests --===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Basic/LangStandard.h"
+#include "clang/CodeGen/BackendUtil.h"
+#include "clang/CodeGen/CodeGenAction.h"
+#include "clang/Frontend/CompilerInstance.h"
+#include "clang/Frontend/TextDiagnosticPrinter.h"
+#include "clang/FrontendTool/Utils.h"
+#include "clang/Lex/PreprocessorOptions.h"
+#include "gtest/gtest.h"
+
+using namespace llvm;
+using namespace clang;
+using namespace clang::frontend;
+
+namespace {
+
+TEST(FrontendOutputTests, TestOutputStream) {
+  auto Invocation = std::make_shared<CompilerInvocation>();
+  Invocation->getPreprocessorOpts().addRemappedFile(
+      "test.cc", MemoryBuffer::getMemBuffer("").release());
+  Invocation->getFrontendOpts().Inputs.push_back(
+      FrontendInputFile("test.cc", Language::CXX));
+  Invocation->getFrontendOpts().ProgramAction = EmitBC;
+  Invocation->getTargetOpts().Triple = "i386-unknown-linux-gnu";
+  CompilerInstance Compiler;
+
+  SmallVector<char, 256> IRBuffer;
+  std::unique_ptr<raw_pwrite_stream> IRStream(
+      new raw_svector_ostream(IRBuffer));
+
+  Compiler.setOutputStream(std::move(IRStream));
+  Compiler.setInvocation(std::move(Invocation));
+  Compiler.createDiagnostics();
+
+  bool Success = ExecuteCompilerInvocation(&Compiler);
+  EXPECT_TRUE(Success);
+  EXPECT_TRUE(!IRBuffer.empty());
+  EXPECT_TRUE(StringRef(IRBuffer.data()).startswith("BC"));
+}
+
+TEST(FrontendOutputTests, TestVerboseOutputStreamShared) {
+  auto Invocation = std::make_shared<CompilerInvocation>();
+  Invocation->getPreprocessorOpts().addRemappedFile(
+      "test.cc", MemoryBuffer::getMemBuffer("invalid").release());
+  Invocation->getFrontendOpts().Inputs.push_back(
+      FrontendInputFile("test.cc", Language::CXX));
+  Invocation->getFrontendOpts().ProgramAction = EmitBC;
+  Invocation->getTargetOpts().Triple = "i386-unknown-linux-gnu";
+  CompilerInstance Compiler;
+
+  std::string VerboseBuffer;
+  raw_string_ostream VerboseStream(VerboseBuffer);
+
+  Compiler.setOutputStream(std::make_unique<raw_null_ostream>());
+  Compiler.setInvocation(std::move(Invocation));
+  IntrusiveRefCntPtr<DiagnosticOptions> DiagOpts = new DiagnosticOptions();
+  Compiler.createDiagnostics(
+      new TextDiagnosticPrinter(llvm::nulls(), &*DiagOpts), true);
+  Compiler.setVerboseOutputStream(VerboseStream);
+
+  bool Success = ExecuteCompilerInvocation(&Compiler);
+  EXPECT_FALSE(Success);
+  EXPECT_TRUE(!VerboseStream.str().empty());
+  EXPECT_TRUE(StringRef(VerboseBuffer.data()).contains("errors generated"));
+}
+
+TEST(FrontendOutputTests, TestVerboseOutputStreamOwned) {
+  std::string VerboseBuffer;
+  bool Success;
+  {
+    auto Invocation = std::make_shared<CompilerInvocation>();
+    Invocation->getPreprocessorOpts().addRemappedFile(
+        "test.cc", MemoryBuffer::getMemBuffer("invalid").release());
+    Invocation->getFrontendOpts().Inputs.push_back(
+        FrontendInputFile("test.cc", Language::CXX));
+    Invocation->getFrontendOpts().ProgramAction = EmitBC;
+    Invocation->getTargetOpts().Triple = "i386-unknown-linux-gnu";
+    CompilerInstance Compiler;
+
+    std::unique_ptr<raw_ostream> VerboseStream =
+        std::make_unique<raw_string_ostream>(VerboseBuffer);
+
+    Compiler.setOutputStream(std::make_unique<raw_null_ostream>());
+    Compiler.setInvocation(std::move(Invocation));
+    IntrusiveRefCntPtr<DiagnosticOptions> DiagOpts = new DiagnosticOptions();
+    Compiler.createDiagnostics(
+        new TextDiagnosticPrinter(llvm::nulls(), &*DiagOpts), true);
+    Compiler.setVerboseOutputStream(std::move(VerboseStream));
+
+    Success = ExecuteCompilerInvocation(&Compiler);
+  }
+  EXPECT_FALSE(Success);
+  EXPECT_TRUE(!VerboseBuffer.empty());
+  EXPECT_TRUE(StringRef(VerboseBuffer.data()).contains("errors generated"));
+}
+}
diff --git a/gnu/llvm/clang/unittests/Frontend/PCHPreambleTest.cpp b/gnu/llvm/clang/unittests/Frontend/PCHPreambleTest.cpp
new file mode 100644
index 00000000000..6136b095949
--- /dev/null
+++ b/gnu/llvm/clang/unittests/Frontend/PCHPreambleTest.cpp
@@ -0,0 +1,265 @@
+//====-- unittests/Frontend/PCHPreambleTest.cpp - FrontendAction tests ---====//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Frontend/ASTUnit.h"
+#include "clang/Frontend/CompilerInvocation.h"
+#include "clang/Frontend/CompilerInstance.h"
+#include "clang/Frontend/FrontendActions.h"
+#include "clang/Frontend/FrontendOptions.h"
+#include "clang/Lex/PreprocessorOptions.h"
+#include "clang/Basic/Diagnostic.h"
+#include "clang/Basic/FileManager.h"
+#include "llvm/Support/FileSystem.h"
+#include "llvm/Support/MemoryBuffer.h"
+#include "llvm/Support/Path.h"
+#include "gtest/gtest.h"
+
+using namespace llvm;
+using namespace clang;
+
+namespace {
+
+class ReadCountingInMemoryFileSystem : public vfs::InMemoryFileSystem
+{
+  std::map<std::string, unsigned> ReadCounts;
+
+public:
+  ErrorOr<std::unique_ptr<vfs::File>> openFileForRead(const Twine &Path) override
+  {
+    SmallVector<char, 128> PathVec;
+    Path.toVector(PathVec);
+    llvm::sys::path::remove_dots(PathVec, true);
+    ++ReadCounts[std::string(PathVec.begin(), PathVec.end())];
+    return InMemoryFileSystem::openFileForRead(Path);
+  }
+
+  unsigned GetReadCount(const Twine &Path) const
+  {
+    auto it = ReadCounts.find(Path.str());
+    return it == ReadCounts.end() ? 0 : it->second;
+  }
+};
+
+class PCHPreambleTest : public ::testing::Test {
+  IntrusiveRefCntPtr<ReadCountingInMemoryFileSystem> VFS;
+  StringMap<std::string> RemappedFiles;
+  std::shared_ptr<PCHContainerOperations> PCHContainerOpts;
+  FileSystemOptions FSOpts;
+
+public:
+  void SetUp() override { ResetVFS(); }
+  void TearDown() override {}
+
+  void ResetVFS() {
+    VFS = new ReadCountingInMemoryFileSystem();
+    // We need the working directory to be set to something absolute,
+    // otherwise it ends up being inadvertently set to the current
+    // working directory in the real file system due to a series of
+    // unfortunate conditions interacting badly.
+    // What's more, this path *must* be absolute on all (real)
+    // filesystems, so just '/' won't work (e.g. on Win32).
+    VFS->setCurrentWorkingDirectory("//./");
+  }
+
+  void AddFile(const std::string &Filename, const std::string &Contents) {
+    ::time_t now;
+    ::time(&now);
+    VFS->addFile(Filename, now, MemoryBuffer::getMemBufferCopy(Contents, Filename));
+  }
+
+  void RemapFile(const std::string &Filename, const std::string &Contents) {
+    RemappedFiles[Filename] = Contents;
+  }
+
+  std::unique_ptr<ASTUnit> ParseAST(const std::string &EntryFile) {
+    PCHContainerOpts = std::make_shared<PCHContainerOperations>();
+    std::shared_ptr<CompilerInvocation> CI(new CompilerInvocation);
+    CI->getFrontendOpts().Inputs.push_back(
+      FrontendInputFile(EntryFile, FrontendOptions::getInputKindForExtension(
+        llvm::sys::path::extension(EntryFile).substr(1))));
+
+    CI->getTargetOpts().Triple = "i386-unknown-linux-gnu";
+
+    CI->getPreprocessorOpts().RemappedFileBuffers = GetRemappedFiles();
+
+    PreprocessorOptions &PPOpts = CI->getPreprocessorOpts();
+    PPOpts.RemappedFilesKeepOriginalName = true;
+
+    IntrusiveRefCntPtr<DiagnosticsEngine>
+      Diags(CompilerInstance::createDiagnostics(new DiagnosticOptions, new DiagnosticConsumer));
+
+    FileManager *FileMgr = new FileManager(FSOpts, VFS);
+
+    std::unique_ptr<ASTUnit> AST = ASTUnit::LoadFromCompilerInvocation(
+        CI, PCHContainerOpts, Diags, FileMgr, false, CaptureDiagsKind::None,
+        /*PrecompilePreambleAfterNParses=*/1);
+    return AST;
+  }
+
+  bool ReparseAST(const std::unique_ptr<ASTUnit> &AST) {
+    bool reparseFailed = AST->Reparse(PCHContainerOpts, GetRemappedFiles(), VFS);
+    return !reparseFailed;
+  }
+
+  unsigned GetFileReadCount(const std::string &Filename) const {
+    return VFS->GetReadCount(Filename);
+  }
+
+private:
+  std::vector<std::pair<std::string, llvm::MemoryBuffer *>>
+  GetRemappedFiles() const {
+    std::vector<std::pair<std::string, llvm::MemoryBuffer *>> Remapped;
+    for (const auto &RemappedFile : RemappedFiles) {
+      std::unique_ptr<MemoryBuffer> buf = MemoryBuffer::getMemBufferCopy(
+        RemappedFile.second, RemappedFile.first());
+      Remapped.emplace_back(RemappedFile.first(), buf.release());
+    }
+    return Remapped;
+  }
+};
+
+TEST_F(PCHPreambleTest, ReparseReusesPreambleWithUnsavedFileNotExistingOnDisk) {
+  std::string Header1 = "//./header1.h";
+  std::string MainName = "//./main.cpp";
+  AddFile(MainName, R"cpp(
+#include "//./header1.h"
+int main() { return ZERO; }
+)cpp");
+  RemapFile(Header1, "#define ZERO 0\n");
+
+  // Parse with header file provided as unsaved file, which does not exist on
+  // disk.
+  std::unique_ptr<ASTUnit> AST(ParseAST(MainName));
+  ASSERT_TRUE(AST.get());
+  ASSERT_FALSE(AST->getDiagnostics().hasErrorOccurred());
+
+  // Reparse and check that the preamble was reused.
+  ASSERT_TRUE(ReparseAST(AST));
+  ASSERT_EQ(AST->getPreambleCounterForTests(), 1U);
+}
+
+TEST_F(PCHPreambleTest, ReparseReusesPreambleAfterUnsavedFileWasCreatedOnDisk) {
+  std::string Header1 = "//./header1.h";
+  std::string MainName = "//./main.cpp";
+  AddFile(MainName, R"cpp(
+#include "//./header1.h"
+int main() { return ZERO; }
+)cpp");
+  RemapFile(Header1, "#define ZERO 0\n");
+
+  // Parse with header file provided as unsaved file, which does not exist on
+  // disk.
+  std::unique_ptr<ASTUnit> AST(ParseAST(MainName));
+  ASSERT_TRUE(AST.get());
+  ASSERT_FALSE(AST->getDiagnostics().hasErrorOccurred());
+
+  // Create the unsaved file also on disk and check that preamble was reused.
+  AddFile(Header1, "#define ZERO 0\n");
+  ASSERT_TRUE(ReparseAST(AST));
+  ASSERT_EQ(AST->getPreambleCounterForTests(), 1U);
+}
+
+TEST_F(PCHPreambleTest,
+       ReparseReusesPreambleAfterUnsavedFileWasRemovedFromDisk) {
+  std::string Header1 = "//./foo/header1.h";
+  std::string MainName = "//./main.cpp";
+  std::string MainFileContent = R"cpp(
+#include "//./foo/header1.h"
+int main() { return ZERO; }
+)cpp";
+  AddFile(MainName, MainFileContent);
+  AddFile(Header1, "#define ZERO 0\n");
+  RemapFile(Header1, "#define ZERO 0\n");
+
+  // Parse with header file provided as unsaved file, which exists on disk.
+  std::unique_ptr<ASTUnit> AST(ParseAST(MainName));
+  ASSERT_TRUE(AST.get());
+  ASSERT_FALSE(AST->getDiagnostics().hasErrorOccurred());
+  ASSERT_EQ(AST->getPreambleCounterForTests(), 1U);
+
+  // Remove the unsaved file from disk and check that the preamble was reused.
+  ResetVFS();
+  AddFile(MainName, MainFileContent);
+  ASSERT_TRUE(ReparseAST(AST));
+  ASSERT_EQ(AST->getPreambleCounterForTests(), 1U);
+}
+
+TEST_F(PCHPreambleTest, ReparseWithOverriddenFileDoesNotInvalidatePreamble) {
+  std::string Header1 = "//./header1.h";
+  std::string Header2 = "//./header2.h";
+  std::string MainName = "//./main.cpp";
+  AddFile(Header1, "");
+  AddFile(Header2, "#pragma once");
+  AddFile(MainName,
+    "#include \"//./foo/../header1.h\"\n"
+    "#include \"//./foo/../header2.h\"\n"
+    "int main() { return ZERO; }");
+  RemapFile(Header1, "static const int ZERO = 0;\n");
+
+  std::unique_ptr<ASTUnit> AST(ParseAST(MainName));
+  ASSERT_TRUE(AST.get());
+  ASSERT_FALSE(AST->getDiagnostics().hasErrorOccurred());
+
+  unsigned initialCounts[] = {
+    GetFileReadCount(MainName),
+    GetFileReadCount(Header1),
+    GetFileReadCount(Header2)
+  };
+
+  ASSERT_TRUE(ReparseAST(AST));
+
+  ASSERT_NE(initialCounts[0], GetFileReadCount(MainName));
+  ASSERT_EQ(initialCounts[1], GetFileReadCount(Header1));
+  ASSERT_EQ(initialCounts[2], GetFileReadCount(Header2));
+}
+
+TEST_F(PCHPreambleTest, ParseWithBom) {
+  std::string Header = "//./header.h";
+  std::string Main = "//./main.cpp";
+  AddFile(Header, "int random() { return 4; }");
+  AddFile(Main,
+    "\xef\xbb\xbf"
+    "#include \"//./header.h\"\n"
+    "int main() { return random() -2; }");
+
+  std::unique_ptr<ASTUnit> AST(ParseAST(Main));
+  ASSERT_TRUE(AST.get());
+  ASSERT_FALSE(AST->getDiagnostics().hasErrorOccurred());
+
+  unsigned HeaderReadCount = GetFileReadCount(Header);
+
+  ASSERT_TRUE(ReparseAST(AST));
+  ASSERT_FALSE(AST->getDiagnostics().hasErrorOccurred());
+  
+  // Check preamble PCH was really reused
+  ASSERT_EQ(HeaderReadCount, GetFileReadCount(Header));
+
+  // Remove BOM
+  RemapFile(Main,
+    "#include \"//./header.h\"\n"
+    "int main() { return random() -2; }");
+
+  ASSERT_TRUE(ReparseAST(AST));
+  ASSERT_FALSE(AST->getDiagnostics().hasErrorOccurred());
+
+  ASSERT_LE(HeaderReadCount, GetFileReadCount(Header));
+  HeaderReadCount = GetFileReadCount(Header);
+
+  // Add BOM back
+  RemapFile(Main,
+    "\xef\xbb\xbf"
+    "#include \"//./header.h\"\n"
+    "int main() { return random() -2; }");
+
+  ASSERT_TRUE(ReparseAST(AST));
+  ASSERT_FALSE(AST->getDiagnostics().hasErrorOccurred());
+
+  ASSERT_LE(HeaderReadCount, GetFileReadCount(Header));
+}
+
+} // anonymous namespace
diff --git a/gnu/llvm/clang/unittests/Frontend/ParsedSourceLocationTest.cpp b/gnu/llvm/clang/unittests/Frontend/ParsedSourceLocationTest.cpp
new file mode 100644
index 00000000000..1539005acd8
--- /dev/null
+++ b/gnu/llvm/clang/unittests/Frontend/ParsedSourceLocationTest.cpp
@@ -0,0 +1,36 @@
+//===- unittests/Frontend/ParsedSourceLocationTest.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
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Frontend/CommandLineSourceLoc.h"
+#include "gtest/gtest.h"
+
+using namespace llvm;
+using namespace clang;
+
+namespace {
+
+TEST(ParsedSourceRange, ParseTest) {
+  auto Check = [](StringRef Value, StringRef Filename, unsigned BeginLine,
+                  unsigned BeginColumn, unsigned EndLine, unsigned EndColumn) {
+    Optional<ParsedSourceRange> PSR = ParsedSourceRange::fromString(Value);
+    ASSERT_TRUE(PSR);
+    EXPECT_EQ(PSR->FileName, Filename);
+    EXPECT_EQ(PSR->Begin.first, BeginLine);
+    EXPECT_EQ(PSR->Begin.second, BeginColumn);
+    EXPECT_EQ(PSR->End.first, EndLine);
+    EXPECT_EQ(PSR->End.second, EndColumn);
+  };
+
+  Check("/Users/test/a-b.cpp:1:2", "/Users/test/a-b.cpp", 1, 2, 1, 2);
+  Check("/Users/test/a-b.cpp:1:2-3:4", "/Users/test/a-b.cpp", 1, 2, 3, 4);
+
+  Check("C:/Users/bob/a-b.cpp:1:2", "C:/Users/bob/a-b.cpp", 1, 2, 1, 2);
+  Check("C:/Users/bob/a-b.cpp:1:2-3:4", "C:/Users/bob/a-b.cpp", 1, 2, 3, 4);
+}
+
+} // anonymous namespace