Basic: Return a reference from FileManager::getVirtualFileSystem, NFC

FileManager constructs a VFS in its constructor if it isn't passed one,
and there's no way to reset it.  Make that contract clear by returning a
reference from its accessor.

https://reviews.llvm.org/D59388

llvm-svn: 357038

11 files changed, 26 insertions, 26 deletions

diff --git a/clang/include/clang/Basic/FileManager.h b/clang/include/clang/Basic/FileManager.h
index b8348269124..96983475f45 100644
--- a/clang/include/clang/Basic/FileManager.h
+++ b/clang/include/clang/Basic/FileManager.h
@@ -221,9 +221,7 @@ public:
   FileSystemOptions &getFileSystemOpts() { return FileSystemOpts; }
   const FileSystemOptions &getFileSystemOpts() const { return FileSystemOpts; }
 
-  IntrusiveRefCntPtr<llvm::vfs::FileSystem> getVirtualFileSystem() const {
-    return FS;
-  }
+  llvm::vfs::FileSystem &getVirtualFileSystem() const { return *FS; }
 
   /// Retrieve a file entry for a "virtual" file that acts as
   /// if there were a file with the given name on disk.
diff --git a/clang/include/clang/Frontend/CompilerInstance.h b/clang/include/clang/Frontend/CompilerInstance.h
index f63ff48f69a..2eb1349f49c 100644
--- a/clang/include/clang/Frontend/CompilerInstance.h
+++ b/clang/include/clang/Frontend/CompilerInstance.h
@@ -380,7 +380,7 @@ public:
   /// {
 
   llvm::vfs::FileSystem &getVirtualFileSystem() const {
-    return *getFileManager().getVirtualFileSystem();
+    return getFileManager().getVirtualFileSystem();
   }
 
   /// }
diff --git a/clang/lib/Frontend/ASTUnit.cpp b/clang/lib/Frontend/ASTUnit.cpp
index 7bc3010fcad..6a78b93b205 100644
--- a/clang/lib/Frontend/ASTUnit.cpp
+++ b/clang/lib/Frontend/ASTUnit.cpp
@@ -1079,7 +1079,7 @@ bool ASTUnit::Parse(std::shared_ptr<PCHContainerOperations> PCHContainerOps,
     return true;
 
   if (VFS && FileMgr)
-    assert(VFS == FileMgr->getVirtualFileSystem() &&
+    assert(VFS == &FileMgr->getVirtualFileSystem() &&
            "VFS passed to Parse and VFS in FileMgr are different");
 
   auto CCInvocation = std::make_shared<CompilerInvocation>(*Invocation);
@@ -1097,7 +1097,7 @@ bool ASTUnit::Parse(std::shared_ptr<PCHContainerOperations> PCHContainerOps,
   // Ensure that Clang has a FileManager with the right VFS, which may have
   // changed above in AddImplicitPreamble.  If VFS is nullptr, rely on
   // createFileManager to create one.
-  if (VFS && FileMgr && FileMgr->getVirtualFileSystem() == VFS)
+  if (VFS && FileMgr && &FileMgr->getVirtualFileSystem() == VFS)
     Clang->setFileManager(&*FileMgr);
   else
     FileMgr = Clang->createFileManager(std::move(VFS));
@@ -1690,7 +1690,7 @@ std::unique_ptr<ASTUnit> ASTUnit::LoadFromCompilerInvocation(
 
   if (AST->LoadFromCompilerInvocation(std::move(PCHContainerOps),
                                       PrecompilePreambleAfterNParses,
-                                      AST->FileMgr->getVirtualFileSystem()))
+                                      &AST->FileMgr->getVirtualFileSystem()))
     return nullptr;
   return AST;
 }
@@ -1797,7 +1797,7 @@ bool ASTUnit::Reparse(std::shared_ptr<PCHContainerOperations> PCHContainerOps,
 
   if (!VFS) {
     assert(FileMgr && "FileMgr is null on Reparse call");
-    VFS = FileMgr->getVirtualFileSystem();
+    VFS = &FileMgr->getVirtualFileSystem();
   }
 
   clearFileLevelDecls();
@@ -2211,18 +2211,18 @@ void ASTUnit::CodeComplete(
   if (Preamble) {
     std::string CompleteFilePath(File);
 
-    auto VFS = FileMgr.getVirtualFileSystem();
-    auto CompleteFileStatus = VFS->status(CompleteFilePath);
+    auto &VFS = FileMgr.getVirtualFileSystem();
+    auto CompleteFileStatus = VFS.status(CompleteFilePath);
     if (CompleteFileStatus) {
       llvm::sys::fs::UniqueID CompleteFileID = CompleteFileStatus->getUniqueID();
 
       std::string MainPath(OriginalSourceFile);
-      auto MainStatus = VFS->status(MainPath);
+      auto MainStatus = VFS.status(MainPath);
       if (MainStatus) {
         llvm::sys::fs::UniqueID MainID = MainStatus->getUniqueID();
         if (CompleteFileID == MainID && Line > 1)
           OverrideMainBuffer = getMainBufferWithPrecompiledPreamble(
-              PCHContainerOps, Inv, VFS, false, Line - 1);
+              PCHContainerOps, Inv, &VFS, false, Line - 1);
       }
     }
   }
@@ -2233,7 +2233,8 @@ void ASTUnit::CodeComplete(
     assert(Preamble &&
            "No preamble was built, but OverrideMainBuffer is not null");
 
-    auto VFS = FileMgr.getVirtualFileSystem();
+    IntrusiveRefCntPtr<llvm::vfs::FileSystem> VFS =
+        &FileMgr.getVirtualFileSystem();
     Preamble->AddImplicitPreamble(Clang->getInvocation(), VFS,
                                   OverrideMainBuffer.get());
     // FIXME: there is no way to update VFS if it was changed by
diff --git a/clang/lib/Frontend/CompilerInstance.cpp b/clang/lib/Frontend/CompilerInstance.cpp
index 6c82a6e9532..559bdb3c0e5 100644
--- a/clang/lib/Frontend/CompilerInstance.cpp
+++ b/clang/lib/Frontend/CompilerInstance.cpp
@@ -169,7 +169,7 @@ static void collectIncludePCH(CompilerInstance &CI,
   std::error_code EC;
   SmallString<128> DirNative;
   llvm::sys::path::native(PCHDir->getName(), DirNative);
-  llvm::vfs::FileSystem &FS = *FileMgr.getVirtualFileSystem();
+  llvm::vfs::FileSystem &FS = FileMgr.getVirtualFileSystem();
   SimpleASTReaderListener Validator(CI.getPreprocessor());
   for (llvm::vfs::directory_iterator Dir = FS.dir_begin(DirNative, EC), DirEnd;
        Dir != DirEnd && !EC; Dir.increment(EC)) {
@@ -296,7 +296,7 @@ CompilerInstance::createDiagnostics(DiagnosticOptions *Opts,
 FileManager *CompilerInstance::createFileManager(
     IntrusiveRefCntPtr<llvm::vfs::FileSystem> VFS) {
   if (!VFS)
-    VFS = FileMgr ? FileMgr->getVirtualFileSystem()
+    VFS = FileMgr ? &FileMgr->getVirtualFileSystem()
                   : createVFSFromCompilerInvocation(getInvocation(),
                                                     getDiagnostics());
   assert(VFS && "FileManager has no VFS?");
diff --git a/clang/lib/Frontend/FrontendAction.cpp b/clang/lib/Frontend/FrontendAction.cpp
index 3392923380f..2f4f5ef64c2 100644
--- a/clang/lib/Frontend/FrontendAction.cpp
+++ b/clang/lib/Frontend/FrontendAction.cpp
@@ -360,7 +360,7 @@ static std::error_code collectModuleHeaderIncludes(
     SmallString<128> DirNative;
     llvm::sys::path::native(UmbrellaDir.Entry->getName(), DirNative);
 
-    llvm::vfs::FileSystem &FS = *FileMgr.getVirtualFileSystem();
+    llvm::vfs::FileSystem &FS = FileMgr.getVirtualFileSystem();
     for (llvm::vfs::recursive_directory_iterator Dir(FS, DirNative, EC), End;
          Dir != End && !EC; Dir.increment(EC)) {
       // Check whether this entry has an extension typically associated with
@@ -714,7 +714,7 @@ bool FrontendAction::BeginSourceFile(CompilerInstance &CI,
       SmallString<128> DirNative;
       llvm::sys::path::native(PCHDir->getName(), DirNative);
       bool Found = false;
-      llvm::vfs::FileSystem &FS = *FileMgr.getVirtualFileSystem();
+      llvm::vfs::FileSystem &FS = FileMgr.getVirtualFileSystem();
       for (llvm::vfs::directory_iterator Dir = FS.dir_begin(DirNative, EC),
                                          DirEnd;
            Dir != DirEnd && !EC; Dir.increment(EC)) {
diff --git a/clang/lib/Lex/HeaderSearch.cpp b/clang/lib/Lex/HeaderSearch.cpp
index 9c92f772c2b..e0ffb8758cf 100644
--- a/clang/lib/Lex/HeaderSearch.cpp
+++ b/clang/lib/Lex/HeaderSearch.cpp
@@ -1579,7 +1579,7 @@ void HeaderSearch::collectAllModules(SmallVectorImpl<Module *> &Modules) {
                                 DirNative);
 
         // Search each of the ".framework" directories to load them as modules.
-        llvm::vfs::FileSystem &FS = *FileMgr.getVirtualFileSystem();
+        llvm::vfs::FileSystem &FS = FileMgr.getVirtualFileSystem();
         for (llvm::vfs::directory_iterator Dir = FS.dir_begin(DirNative, EC),
                                            DirEnd;
              Dir != DirEnd && !EC; Dir.increment(EC)) {
@@ -1650,7 +1650,7 @@ void HeaderSearch::loadSubdirectoryModuleMaps(DirectoryLookup &SearchDir) {
   FileMgr.makeAbsolutePath(Dir);
   SmallString<128> DirNative;
   llvm::sys::path::native(Dir, DirNative);
-  llvm::vfs::FileSystem &FS = *FileMgr.getVirtualFileSystem();
+  llvm::vfs::FileSystem &FS = FileMgr.getVirtualFileSystem();
   for (llvm::vfs::directory_iterator Dir = FS.dir_begin(DirNative, EC), DirEnd;
        Dir != DirEnd && !EC; Dir.increment(EC)) {
     bool IsFramework = llvm::sys::path::extension(Dir->path()) == ".framework";
diff --git a/clang/lib/Lex/ModuleMap.cpp b/clang/lib/Lex/ModuleMap.cpp
index 31eff14553e..b597c6dafcb 100644
--- a/clang/lib/Lex/ModuleMap.cpp
+++ b/clang/lib/Lex/ModuleMap.cpp
@@ -1021,7 +1021,7 @@ Module *ModuleMap::inferFrameworkModule(const DirectoryEntry *FrameworkDir,
     = StringRef(FrameworkDir->getName());
   llvm::sys::path::append(SubframeworksDirName, "Frameworks");
   llvm::sys::path::native(SubframeworksDirName);
-  llvm::vfs::FileSystem &FS = *FileMgr.getVirtualFileSystem();
+  llvm::vfs::FileSystem &FS = FileMgr.getVirtualFileSystem();
   for (llvm::vfs::directory_iterator
            Dir = FS.dir_begin(SubframeworksDirName, EC),
            DirEnd;
@@ -2397,7 +2397,7 @@ void ModuleMapParser::parseUmbrellaDirDecl(SourceLocation UmbrellaLoc) {
     std::error_code EC;
     SmallVector<Module::Header, 6> Headers;
     llvm::vfs::FileSystem &FS =
-        *SourceMgr.getFileManager().getVirtualFileSystem();
+        SourceMgr.getFileManager().getVirtualFileSystem();
     for (llvm::vfs::recursive_directory_iterator I(FS, Dir->getName(), EC), E;
          I != E && !EC; I.increment(EC)) {
       if (const FileEntry *FE = SourceMgr.getFileManager().getFile(I->path())) {
diff --git a/clang/lib/Lex/PPLexerChange.cpp b/clang/lib/Lex/PPLexerChange.cpp
index 2f1e67c67c4..5f547d9f1cc 100644
--- a/clang/lib/Lex/PPLexerChange.cpp
+++ b/clang/lib/Lex/PPLexerChange.cpp
@@ -270,7 +270,7 @@ void Preprocessor::diagnoseMissingHeaderInUmbrellaDir(const Module &Mod) {
 
   ModuleMap &ModMap = getHeaderSearchInfo().getModuleMap();
   const DirectoryEntry *Dir = Mod.getUmbrellaDir().Entry;
-  llvm::vfs::FileSystem &FS = *FileMgr.getVirtualFileSystem();
+  llvm::vfs::FileSystem &FS = FileMgr.getVirtualFileSystem();
   std::error_code EC;
   for (llvm::vfs::recursive_directory_iterator Entry(FS, Dir->getName(), EC),
        End;
diff --git a/clang/lib/Sema/SemaCodeComplete.cpp b/clang/lib/Sema/SemaCodeComplete.cpp
index 0946a24676d..2412d919ec9 100644
--- a/clang/lib/Sema/SemaCodeComplete.cpp
+++ b/clang/lib/Sema/SemaCodeComplete.cpp
@@ -8379,7 +8379,8 @@ void Sema::CodeCompleteIncludedFile(llvm::StringRef Dir, bool Angled) {
   // We need the native slashes for the actual file system interactions.
   SmallString<128> NativeRelDir = StringRef(RelDir);
   llvm::sys::path::native(NativeRelDir);
-  auto FS = getSourceManager().getFileManager().getVirtualFileSystem();
+  llvm::vfs::FileSystem &FS =
+      getSourceManager().getFileManager().getVirtualFileSystem();
 
   ResultBuilder Results(*this, CodeCompleter->getAllocator(),
                         CodeCompleter->getCodeCompletionTUInfo(),
@@ -8425,7 +8426,7 @@ void Sema::CodeCompleteIncludedFile(llvm::StringRef Dir, bool Angled) {
 
     std::error_code EC;
     unsigned Count = 0;
-    for (auto It = FS->dir_begin(Dir, EC);
+    for (auto It = FS.dir_begin(Dir, EC);
          !EC && It != llvm::vfs::directory_iterator(); It.increment(EC)) {
       if (++Count == 2500) // If we happen to hit a huge directory,
         break;             // bail out early so we're not too slow.
diff --git a/clang/lib/Tooling/Tooling.cpp b/clang/lib/Tooling/Tooling.cpp
index c82be38ca15..68760ef7569 100644
--- a/clang/lib/Tooling/Tooling.cpp
+++ b/clang/lib/Tooling/Tooling.cpp
@@ -301,7 +301,7 @@ bool ToolInvocation::run() {
       DiagConsumer ? DiagConsumer : &DiagnosticPrinter, false);
 
   const std::unique_ptr<driver::Driver> Driver(
-      newDriver(&Diagnostics, BinaryName, Files->getVirtualFileSystem()));
+      newDriver(&Diagnostics, BinaryName, &Files->getVirtualFileSystem()));
   // The "input file not found" diagnostics from the driver are useful.
   // The driver is only aware of the VFS working directory, but some clients
   // change this at the FileManager level instead.
diff --git a/clang/unittests/AST/ASTImporterTest.cpp b/clang/unittests/AST/ASTImporterTest.cpp
index d6bd1349856..a282e2a0244 100644
--- a/clang/unittests/AST/ASTImporterTest.cpp
+++ b/clang/unittests/AST/ASTImporterTest.cpp
@@ -44,7 +44,7 @@ createVirtualFileIfNeeded(ASTUnit *ToAST, StringRef FileName,
   assert(ToAST);
   ASTContext &ToCtx = ToAST->getASTContext();
   auto *OFS = static_cast<llvm::vfs::OverlayFileSystem *>(
-      ToCtx.getSourceManager().getFileManager().getVirtualFileSystem().get());
+      &ToCtx.getSourceManager().getFileManager().getVirtualFileSystem());
   auto *MFS = static_cast<llvm::vfs::InMemoryFileSystem *>(
       OFS->overlays_begin()->get());
   MFS->addFile(FileName, 0, std::move(Buffer));