Reapply "[NFC] Explicitly pass a VFS when creating DiagnosticsEngine (#115852)"

This reverts commit a1153cd with fixes
to lldb breakages.

Fixes #117145.

Author: kadircet

clang-tools-extra/clang-include-fixer/IncludeFixer.cpp

@@ -95,7 +95,8 @@ bool IncludeFixerActionFactory::runInvocation(
 
   // Create the compiler's actual diagnostics engine. We want to drop all
   // diagnostics here.
-  Compiler.createDiagnostics(new clang::IgnoringDiagConsumer,
+  Compiler.createDiagnostics(Files->getVirtualFileSystem(),
+                             new clang::IgnoringDiagConsumer,
                              /*ShouldOwnClient=*/true);
   Compiler.createSourceManager(*Files);
 

clang-tools-extra/clangd/Compiler.cpp

@@ -110,8 +110,8 @@ buildCompilerInvocation(const ParseInputs &Inputs, clang::DiagnosticConsumer &D,
   CIOpts.VFS = Inputs.TFS->view(Inputs.CompileCommand.Directory);
   CIOpts.CC1Args = CC1Args;
   CIOpts.RecoverOnError = true;
-  CIOpts.Diags =
-      CompilerInstance::createDiagnostics(new DiagnosticOptions, &D, false);
+  CIOpts.Diags = CompilerInstance::createDiagnostics(
+      *CIOpts.VFS, new DiagnosticOptions, &D, false);
   CIOpts.ProbePrecompiled = false;
   std::unique_ptr<CompilerInvocation> CI = createInvocation(ArgStrs, CIOpts);
   if (!CI)
@@ -148,7 +148,7 @@ prepareCompilerInstance(std::unique_ptr<clang::CompilerInvocation> CI,
   auto Clang = std::make_unique<CompilerInstance>(
       std::make_shared<PCHContainerOperations>());
   Clang->setInvocation(std::move(CI));
-  Clang->createDiagnostics(&DiagsClient, false);
+  Clang->createDiagnostics(*VFS, &DiagsClient, false);
 
   if (auto VFSWithRemapping = createVFSFromCompilerInvocation(
           Clang->getInvocation(), Clang->getDiagnostics(), VFS))

clang-tools-extra/clangd/ModulesBuilder.cpp

@@ -188,7 +188,8 @@ bool IsModuleFileUpToDate(PathRef ModuleFilePath,
 
   clang::clangd::IgnoreDiagnostics IgnoreDiags;
   IntrusiveRefCntPtr<DiagnosticsEngine> Diags =
-      CompilerInstance::createDiagnostics(new DiagnosticOptions, &IgnoreDiags,
+      CompilerInstance::createDiagnostics(*VFS, new DiagnosticOptions,
+                                          &IgnoreDiags,
                                           /*ShouldOwnClient=*/false);
 
   LangOptions LangOpts;

clang-tools-extra/clangd/Preamble.cpp

@@ -613,8 +613,9 @@ buildPreamble(PathRef FileName, CompilerInvocation CI,
         for (const auto &L : ASTListeners)
           L->sawDiagnostic(D, Diag);
       });
+  auto VFS = Inputs.TFS->view(Inputs.CompileCommand.Directory);
   llvm::IntrusiveRefCntPtr<DiagnosticsEngine> PreambleDiagsEngine =
-      CompilerInstance::createDiagnostics(&CI.getDiagnosticOpts(),
+      CompilerInstance::createDiagnostics(*VFS, &CI.getDiagnosticOpts(),
                                           &PreambleDiagnostics,
                                           /*ShouldOwnClient=*/false);
   const Config &Cfg = Config::current();
@@ -651,7 +652,6 @@ buildPreamble(PathRef FileName, CompilerInvocation CI,
         for (const auto &L : ASTListeners)
           L->beforeExecute(CI);
       });
-  auto VFS = Inputs.TFS->view(Inputs.CompileCommand.Directory);
   llvm::SmallString<32> AbsFileName(FileName);
   VFS->makeAbsolute(AbsFileName);
   auto StatCache = std::make_shared<PreambleFileStatusCache>(AbsFileName);

clang-tools-extra/include-cleaner/unittests/RecordTest.cpp

@@ -609,15 +609,6 @@ TEST_F(PragmaIncludeTest, ExportInUnnamedBuffer) {
   )cpp";
   Inputs.ExtraFiles["foo.h"] = "";
 
-  auto Clang = std::make_unique<CompilerInstance>(
-      std::make_shared<PCHContainerOperations>());
-  Clang->createDiagnostics();
-
-  Clang->setInvocation(std::make_unique<CompilerInvocation>());
-  ASSERT_TRUE(CompilerInvocation::CreateFromArgs(
-      Clang->getInvocation(), {Filename.data()}, Clang->getDiagnostics(),
-      "clang"));
-
   // Create unnamed memory buffers for all the files.
   auto VFS = llvm::makeIntrusiveRefCnt<llvm::vfs::InMemoryFileSystem>();
   VFS->addFile(Filename, /*ModificationTime=*/0,
@@ -626,6 +617,16 @@ TEST_F(PragmaIncludeTest, ExportInUnnamedBuffer) {
     VFS->addFile(Extra.getKey(), /*ModificationTime=*/0,
                  llvm::MemoryBuffer::getMemBufferCopy(Extra.getValue(),
                                                       /*BufferName=*/""));
+
+  auto Clang = std::make_unique<CompilerInstance>(
+      std::make_shared<PCHContainerOperations>());
+  Clang->createDiagnostics(*VFS);
+
+  Clang->setInvocation(std::make_unique<CompilerInvocation>());
+  ASSERT_TRUE(CompilerInvocation::CreateFromArgs(
+      Clang->getInvocation(), {Filename.data()}, Clang->getDiagnostics(),
+      "clang"));
+
   auto *FM = Clang->createFileManager(VFS);
   ASSERT_TRUE(Clang->ExecuteAction(*Inputs.MakeAction()));
   EXPECT_THAT(

clang/include/clang/Frontend/CompilerInstance.h

@@ -675,13 +675,17 @@ class CompilerInstance : public ModuleLoader {
   /// Note that this routine also replaces the diagnostic client,
   /// allocating one if one is not provided.
   ///
+  /// \param VFS is used for any IO needed when creating DiagnosticsEngine. It
+  /// doesn't replace VFS in the CompilerInstance (if any).
+  ///
   /// \param Client If non-NULL, a diagnostic client that will be
   /// attached to (and, then, owned by) the DiagnosticsEngine inside this AST
   /// unit.
   ///
   /// \param ShouldOwnClient If Client is non-NULL, specifies whether
   /// the diagnostic object should take ownership of the client.
-  void createDiagnostics(DiagnosticConsumer *Client = nullptr,
+  void createDiagnostics(llvm::vfs::FileSystem &VFS,
+                         DiagnosticConsumer *Client = nullptr,
                          bool ShouldOwnClient = true);
 
   /// Create a DiagnosticsEngine object with a the TextDiagnosticPrinter.
@@ -702,10 +706,11 @@ class CompilerInstance : public ModuleLoader {
   /// used by some diagnostics printers (for logging purposes only).
   ///
   /// \return The new object on success, or null on failure.
-  static IntrusiveRefCntPtr<DiagnosticsEngine> createDiagnostics(
-      DiagnosticOptions *Opts, DiagnosticConsumer *Client = nullptr,
-      bool ShouldOwnClient = true, const CodeGenOptions *CodeGenOpts = nullptr,
-      IntrusiveRefCntPtr<llvm::vfs::FileSystem> VFS = nullptr);
+  static IntrusiveRefCntPtr<DiagnosticsEngine>
+  createDiagnostics(llvm::vfs::FileSystem &VFS, DiagnosticOptions *Opts,
+                    DiagnosticConsumer *Client = nullptr,
+                    bool ShouldOwnClient = true,
+                    const CodeGenOptions *CodeGenOpts = nullptr);
 
   /// Create the file manager and replace any existing one with it.
   ///

clang/lib/Frontend/CompilerInstance.cpp

@@ -332,23 +332,20 @@ static void SetupSerializedDiagnostics(DiagnosticOptions *DiagOpts,
   }
 }
 
-void CompilerInstance::createDiagnostics(DiagnosticConsumer *Client,
+void CompilerInstance::createDiagnostics(llvm::vfs::FileSystem &VFS,
+                                         DiagnosticConsumer *Client,
                                          bool ShouldOwnClient) {
-  Diagnostics = createDiagnostics(
-      &getDiagnosticOpts(), Client, ShouldOwnClient, &getCodeGenOpts(),
-      FileMgr ? FileMgr->getVirtualFileSystemPtr() : nullptr);
+  Diagnostics = createDiagnostics(VFS, &getDiagnosticOpts(), Client,
+                                  ShouldOwnClient, &getCodeGenOpts());
 }
 
 IntrusiveRefCntPtr<DiagnosticsEngine> CompilerInstance::createDiagnostics(
-    DiagnosticOptions *Opts, DiagnosticConsumer *Client, bool ShouldOwnClient,
-    const CodeGenOptions *CodeGenOpts,
-    llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem> VFS) {
+    llvm::vfs::FileSystem &VFS, DiagnosticOptions *Opts,
+    DiagnosticConsumer *Client, bool ShouldOwnClient,
+    const CodeGenOptions *CodeGenOpts) {
   IntrusiveRefCntPtr<DiagnosticIDs> DiagID(new DiagnosticIDs());
-  IntrusiveRefCntPtr<DiagnosticsEngine>
-      Diags(new DiagnosticsEngine(DiagID, Opts));
-
-  if (!VFS)
-    VFS = llvm::vfs::getRealFileSystem();
+  IntrusiveRefCntPtr<DiagnosticsEngine> Diags(
+      new DiagnosticsEngine(DiagID, Opts));
 
   // Create the diagnostic client for reporting errors or for
   // implementing -verify.
@@ -372,7 +369,7 @@ IntrusiveRefCntPtr<DiagnosticsEngine> CompilerInstance::createDiagnostics(
                                Opts->DiagnosticSerializationFile);
 
   // Configure our handling of diagnostics.
-  ProcessWarningOptions(*Diags, *Opts, *VFS);
+  ProcessWarningOptions(*Diags, *Opts, VFS);
 
   return Diags;
 }
@@ -1240,9 +1237,10 @@ compileModuleImpl(CompilerInstance &ImportingInstance, SourceLocation ImportLoc,
   auto &Inv = *Invocation;
   Instance.setInvocation(std::move(Invocation));
 
-  Instance.createDiagnostics(new ForwardingDiagnosticConsumer(
-                                   ImportingInstance.getDiagnosticClient()),
-                             /*ShouldOwnClient=*/true);
+  Instance.createDiagnostics(
+      ImportingInstance.getVirtualFileSystem(),
+      new ForwardingDiagnosticConsumer(ImportingInstance.getDiagnosticClient()),
+      /*ShouldOwnClient=*/true);
 
   if (llvm::is_contained(DiagOpts.SystemHeaderWarningsModules, ModuleName))
     Instance.getDiagnostics().setSuppressSystemWarnings(false);

clang/lib/Frontend/CreateInvocationFromCommandLine.cpp

@@ -22,6 +22,7 @@
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/Option/ArgList.h"
+#include "llvm/Support/VirtualFileSystem.h"
 #include "llvm/TargetParser/Host.h"
 using namespace clang;
 using namespace llvm::opt;
@@ -32,7 +33,9 @@ clang::createInvocation(ArrayRef<const char *> ArgList,
   assert(!ArgList.empty());
   auto Diags = Opts.Diags
                    ? std::move(Opts.Diags)
-                   : CompilerInstance::createDiagnostics(new DiagnosticOptions);
+                   : CompilerInstance::createDiagnostics(
+                         Opts.VFS ? *Opts.VFS : *llvm::vfs::getRealFileSystem(),
+                         new DiagnosticOptions);
 
   SmallVector<const char *, 16> Args(ArgList);
 

clang/lib/Frontend/Rewrite/FrontendActions.cpp

@@ -247,6 +247,7 @@ class RewriteIncludesAction::RewriteImportsListener : public ASTReaderListener {
     Instance.setInvocation(
         std::make_shared<CompilerInvocation>(CI.getInvocation()));
     Instance.createDiagnostics(
+        CI.getVirtualFileSystem(),
         new ForwardingDiagnosticConsumer(CI.getDiagnosticClient()),
         /*ShouldOwnClient=*/true);
     Instance.getFrontendOpts().DisableFree = false;

clang/lib/Interpreter/Interpreter.cpp

@@ -15,6 +15,7 @@
 #include "IncrementalExecutor.h"
 #include "IncrementalParser.h"
 #include "InterpreterUtils.h"
+#include "llvm/Support/VirtualFileSystem.h"
 #ifdef __EMSCRIPTEN__
 #include "Wasm.h"
 #endif // __EMSCRIPTEN__
@@ -106,7 +107,7 @@ CreateCI(const llvm::opt::ArgStringList &Argv) {
         CompilerInvocation::GetResourcesPath(Argv[0], nullptr);
 
   // Create the actual diagnostics engine.
-  Clang->createDiagnostics();
+  Clang->createDiagnostics(*llvm::vfs::getRealFileSystem());
   if (!Clang->hasDiagnostics())
     return llvm::createStringError(llvm::errc::not_supported,
                                    "Initialization failed. "