//===--- ARCMT.cpp - Migration to ARC mode --------------------------------===//

//

// 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 "Internals.h"

#include "clang/ARCMigrate/ARCMT.h"

#include "clang/AST/ASTConsumer.h"

#include "clang/Basic/DiagnosticCategories.h"

#include "clang/Frontend/ASTUnit.h"

#include "clang/Frontend/CompilerInstance.h"

#include "clang/Frontend/FrontendAction.h"

#include "clang/Frontend/TextDiagnosticPrinter.h"

#include "clang/Frontend/Utils.h"

#include "clang/Lex/Preprocessor.h"

#include "clang/Lex/PreprocessorOptions.h"

#include "clang/Rewrite/Core/Rewriter.h"

#include "clang/Sema/SemaDiagnostic.h"

#include "clang/Serialization/ASTReader.h"

#include "llvm/ADT/Triple.h"

#include "llvm/Support/MemoryBuffer.h"

#include <utility>

using namespace clang;

using namespace arcmt;

bool CapturedDiagList::clearDiagnostic(ArrayRef<unsigned> IDs,

                                       SourceRange range) {

  if (range.isInvalid())

    return false;

  bool cleared = false;

  ListTy::iterator I = List.begin();

  while (I != List.end()) {

    FullSourceLoc diagLoc = I->getLocation();

    if ((IDs.empty() || // empty means clear all diagnostics in the range.

         llvm::is_contained(IDs, I->getID())) &&

        
!diagLoc.isBeforeInTranslationUnitThan(range.getBegin())3.63k
 &&

        
(3.30k
diagLoc == range.getEnd()3.30k
 ||

         
diagLoc.isBeforeInTranslationUnitThan(range.getEnd())2.74k
)) {

      cleared = true;

      ListTy::iterator eraseS = I++;

      if (eraseS->getLevel() != DiagnosticsEngine::Note)

        
while (596
I != List.end() && 
I->getLevel() == DiagnosticsEngine::Note884
)

          ++I;

      // Clear the diagnostic and any notes following it.

      I = List.erase(eraseS, I);

      continue;

    }

    ++I;

  }

  return cleared;

}

bool CapturedDiagList::hasDiagnostic(ArrayRef<unsigned> IDs,

                                     SourceRange range) const {

  if (range.isInvalid())

    return false;

  ListTy::const_iterator I = List.begin();

  while (I != List.end()) {

    FullSourceLoc diagLoc = I->getLocation();

    if ((IDs.empty() || // empty means any diagnostic in the range.

         llvm::find(IDs, I->getID()) != IDs.end()) &&

        
!diagLoc.isBeforeInTranslationUnitThan(range.getBegin())1.33k
 &&

        
(876
diagLoc == range.getEnd()876
 ||

         
diagLoc.isBeforeInTranslationUnitThan(range.getEnd())382
)) {

      return true;

    }

    ++I;

  }

  return false;

}

void CapturedDiagList::reportDiagnostics(DiagnosticsEngine &Diags) const {

  for (ListTy::const_iterator I = List.begin(), E = List.end(); I != E; 
++I150
)

    Diags.Report(*I);

}

bool CapturedDiagList::hasErrors() const {

  for (ListTy::const_iterator I = List.begin(), E = List.end(); I != E; 
++I0
)

    if (I->getLevel() >= DiagnosticsEngine::Error)

      return true;

  return false;

}

namespace {

class CaptureDiagnosticConsumer : public DiagnosticConsumer {

  DiagnosticsEngine &Diags;

  DiagnosticConsumer &DiagClient;

  CapturedDiagList &CapturedDiags;

  bool HasBegunSourceFile;

public:

  CaptureDiagnosticConsumer(DiagnosticsEngine &diags,

                            DiagnosticConsumer &client,

                            CapturedDiagList &capturedDiags)

    : Diags(diags), DiagClient(client), CapturedDiags(capturedDiags),

      HasBegunSourceFile(false) { }

  void BeginSourceFile(const LangOptions &Opts,

                       const Preprocessor *PP) override {

    // Pass BeginSourceFile message onto DiagClient on first call.

    // The corresponding EndSourceFile call will be made from an

    // explicit call to FinishCapture.

    if (!HasBegunSourceFile) {

      DiagClient.BeginSourceFile(Opts, PP);

      HasBegunSourceFile = true;

    }

  }

  void FinishCapture() {

    // Call EndSourceFile on DiagClient on completion of capture to

    // enable VerifyDiagnosticConsumer to check diagnostics *after*

    // it has received the diagnostic list.

    if (HasBegunSourceFile) {

      DiagClient.EndSourceFile();

      HasBegunSourceFile = false;

    }

  }

  ~CaptureDiagnosticConsumer() override {

    assert(!HasBegunSourceFile && "FinishCapture not called!");

  }

  void HandleDiagnostic(DiagnosticsEngine::Level level,

                        const Diagnostic &Info) override {

    if (DiagnosticIDs::isARCDiagnostic(Info.getID()) ||

        
level >= DiagnosticsEngine::Error590
 || 
level == DiagnosticsEngine::Note367
) {

      if (Info.getLocation().isValid())

        CapturedDiags.push_back(StoredDiagnostic(level, Info));

      return;

    }

    // Non-ARC warnings are ignored.

    Diags.setLastDiagnosticIgnored(true);

  }

};

} // end anonymous namespace

static bool HasARCRuntime(CompilerInvocation &origCI) {

  // This duplicates some functionality from Darwin::AddDeploymentTarget

  // but this function is well defined, so keep it decoupled from the driver

  // and avoid unrelated complications.

  llvm::Triple triple(origCI.getTargetOpts().Triple);

  if (triple.isiOS())

    return triple.getOSMajorVersion() >= 5;

  if (triple.isWatchOS())

    return true;

  if (triple.getOS() == llvm::Triple::Darwin)

    return triple.getOSMajorVersion() >= 11;

  if (triple.getOS() == llvm::Triple::MacOSX) {

    unsigned Major, Minor, Micro;

    triple.getOSVersion(Major, Minor, Micro);

    return Major > 10 || (Major == 10 && Minor >= 7);

  }

  return false;

}

static CompilerInvocation *

createInvocationForMigration(CompilerInvocation &origCI,

                             const PCHContainerReader &PCHContainerRdr) {

  std::unique_ptr<CompilerInvocation> CInvok;

  CInvok.reset(new CompilerInvocation(origCI));

  PreprocessorOptions &PPOpts = CInvok->getPreprocessorOpts();

  if (!PPOpts.ImplicitPCHInclude.empty()) {

    // We can't use a PCH because it was likely built in non-ARC mode and we

    // want to parse in ARC. Include the original header.

    FileManager FileMgr(origCI.getFileSystemOpts());

    IntrusiveRefCntPtr<DiagnosticIDs> DiagID(new DiagnosticIDs());

    IntrusiveRefCntPtr<DiagnosticsEngine> Diags(

        new DiagnosticsEngine(DiagID, &origCI.getDiagnosticOpts(),

                              new IgnoringDiagConsumer()));

    std::string OriginalFile = ASTReader::getOriginalSourceFile(

        PPOpts.ImplicitPCHInclude, FileMgr, PCHContainerRdr, *Diags);

    if (!OriginalFile.empty())

      PPOpts.Includes.insert(PPOpts.Includes.begin(), OriginalFile);

    PPOpts.ImplicitPCHInclude.clear();

  }

  std::string define = std::string(getARCMTMacroName());

  define += '=';

  CInvok->getPreprocessorOpts().addMacroDef(define);

  CInvok->getLangOpts()->ObjCAutoRefCount = true;

  CInvok->getLangOpts()->setGC(LangOptions::NonGC);

  CInvok->getDiagnosticOpts().ErrorLimit = 0;

  CInvok->getDiagnosticOpts().PedanticErrors = 0;

  // Ignore -Werror flags when migrating.

  std::vector<std::string> WarnOpts;

  for (std::vector<std::string>::iterator

         I = CInvok->getDiagnosticOpts().Warnings.begin(),

         E = CInvok->getDiagnosticOpts().Warnings.end(); I != E; 
++I3
) {

    if (!StringRef(*I).startswith("error"))

      WarnOpts.push_back(*I);

  }

  WarnOpts.push_back("error=arc-unsafe-retained-assign");

  CInvok->getDiagnosticOpts().Warnings = std::move(WarnOpts);

  CInvok->getLangOpts()->ObjCWeakRuntime = HasARCRuntime(origCI);

  CInvok->getLangOpts()->ObjCWeak = CInvok->getLangOpts()->ObjCWeakRuntime;

  return CInvok.release();

}

static void emitPremigrationErrors(const CapturedDiagList &arcDiags,

                                   DiagnosticOptions *diagOpts,

                                   Preprocessor &PP) {

  TextDiagnosticPrinter printer(llvm::errs(), diagOpts);

  IntrusiveRefCntPtr<DiagnosticIDs> DiagID(new DiagnosticIDs());

  IntrusiveRefCntPtr<DiagnosticsEngine> Diags(

      new DiagnosticsEngine(DiagID, diagOpts, &printer,

                            /*ShouldOwnClient=*/false));

  Diags->setSourceManager(&PP.getSourceManager());

  printer.BeginSourceFile(PP.getLangOpts(), &PP);

  arcDiags.reportDiagnostics(*Diags);

  printer.EndSourceFile();

}

//===----------------------------------------------------------------------===//

// checkForManualIssues.

//===----------------------------------------------------------------------===//

bool arcmt::checkForManualIssues(

    CompilerInvocation &origCI, const FrontendInputFile &Input,

    std::shared_ptr<PCHContainerOperations> PCHContainerOps,

    DiagnosticConsumer *DiagClient, bool emitPremigrationARCErrors,

    StringRef plistOut) {

  if (!origCI.getLangOpts()->ObjC)

    return false;

  LangOptions::GCMode OrigGCMode = origCI.getLangOpts()->getGC();

  bool NoNSAllocReallocError = origCI.getMigratorOpts().NoNSAllocReallocError;

  bool NoFinalizeRemoval = origCI.getMigratorOpts().NoFinalizeRemoval;

  std::vector<TransformFn> transforms = arcmt::getAllTransformations(OrigGCMode,

                                                                     NoFinalizeRemoval);

  assert(!transforms.empty());

  std::unique_ptr<CompilerInvocation> CInvok;

  CInvok.reset(

      createInvocationForMigration(origCI, PCHContainerOps->getRawReader()));

  CInvok->getFrontendOpts().Inputs.clear();

  CInvok->getFrontendOpts().Inputs.push_back(Input);

  CapturedDiagList capturedDiags;

  assert(DiagClient);

  IntrusiveRefCntPtr<DiagnosticIDs> DiagID(new DiagnosticIDs());

  IntrusiveRefCntPtr<DiagnosticsEngine> Diags(

      new DiagnosticsEngine(DiagID, &origCI.getDiagnosticOpts(),

                            DiagClient, /*ShouldOwnClient=*/false));

  // Filter of all diagnostics.

  CaptureDiagnosticConsumer errRec(*Diags, *DiagClient, capturedDiags);

  Diags->setClient(&errRec, /*ShouldOwnClient=*/false);

  std::unique_ptr<ASTUnit> Unit(ASTUnit::LoadFromCompilerInvocationAction(

      std::move(CInvok), PCHContainerOps, Diags));

  if (!Unit) {

    errRec.FinishCapture();

    return true;

  }

  // Don't filter diagnostics anymore.

  Diags->setClient(DiagClient, /*ShouldOwnClient=*/false);

  ASTContext &Ctx = Unit->getASTContext();

  if (Diags->hasFatalErrorOccurred()) {

    Diags->Reset();

    DiagClient->BeginSourceFile(Ctx.getLangOpts(), &Unit->getPreprocessor());

    capturedDiags.reportDiagnostics(*Diags);

    DiagClient->EndSourceFile();

    errRec.FinishCapture();

    return true;

  }

  if (emitPremigrationARCErrors)

    emitPremigrationErrors(capturedDiags, &origCI.getDiagnosticOpts(),

                           Unit->getPreprocessor());

  if (!plistOut.empty()) {

    SmallVector<StoredDiagnostic, 8> arcDiags;

    for (CapturedDiagList::iterator

           I = capturedDiags.begin(), E = capturedDiags.end(); I != E; 
++I1
)

      arcDiags.push_back(*I);

    writeARCDiagsToPlist(std::string(plistOut), arcDiags,

                         Ctx.getSourceManager(), Ctx.getLangOpts());

  }

  // After parsing of source files ended, we want to reuse the

  // diagnostics objects to emit further diagnostics.

  // We call BeginSourceFile because DiagnosticConsumer requires that

  // diagnostics with source range information are emitted only in between

  // BeginSourceFile() and EndSourceFile().

  DiagClient->BeginSourceFile(Ctx.getLangOpts(), &Unit->getPreprocessor());

  // No macros will be added since we are just checking and we won't modify

  // source code.

  std::vector<SourceLocation> ARCMTMacroLocs;

  TransformActions testAct(*Diags, capturedDiags, Ctx, Unit->getPreprocessor());

  MigrationPass pass(Ctx, OrigGCMode, Unit->getSema(), testAct, capturedDiags,

                     ARCMTMacroLocs);

  pass.setNoFinalizeRemoval(NoFinalizeRemoval);

  if (!NoNSAllocReallocError)

    Diags->setSeverity(diag::warn_arcmt_nsalloc_realloc, diag::Severity::Error,

                       SourceLocation());

  for (unsigned i=0, e = transforms.size(); i != e; 
++i102
)

    transforms[i](pass);

  capturedDiags.reportDiagnostics(*Diags);

  DiagClient->EndSourceFile();

  errRec.FinishCapture();

  return capturedDiags.hasErrors() || 
testAct.hasReportedErrors()39
;

}

//===----------------------------------------------------------------------===//

// applyTransformations.

//===----------------------------------------------------------------------===//

static bool

applyTransforms(CompilerInvocation &origCI, const FrontendInputFile &Input,

                std::shared_ptr<PCHContainerOperations> PCHContainerOps,

                DiagnosticConsumer *DiagClient, StringRef outputDir,

                bool emitPremigrationARCErrors, StringRef plistOut) {

  if (!origCI.getLangOpts()->ObjC)

    return false;

  LangOptions::GCMode OrigGCMode = origCI.getLangOpts()->getGC();

  // Make sure checking is successful first.

  CompilerInvocation CInvokForCheck(origCI);

  if (arcmt::checkForManualIssues(CInvokForCheck, Input, PCHContainerOps,

                                  DiagClient, emitPremigrationARCErrors,

                                  plistOut))

    return true;

  CompilerInvocation CInvok(origCI);

  CInvok.getFrontendOpts().Inputs.clear();

  CInvok.getFrontendOpts().Inputs.push_back(Input);

  MigrationProcess migration(CInvok, PCHContainerOps, DiagClient, outputDir);

  bool NoFinalizeRemoval = origCI.getMigratorOpts().NoFinalizeRemoval;

  std::vector<TransformFn> transforms = arcmt::getAllTransformations(OrigGCMode,

                                                                     NoFinalizeRemoval);

  assert(!transforms.empty());

  for (unsigned i=0, e = transforms.size(); i != e; 
++i20
) {

    bool err = migration.applyTransform(transforms[i]);

    if (err) 
return true0
;

  }

  IntrusiveRefCntPtr<DiagnosticIDs> DiagID(new DiagnosticIDs());

  IntrusiveRefCntPtr<DiagnosticsEngine> Diags(

      new DiagnosticsEngine(DiagID, &origCI.getDiagnosticOpts(),

                            DiagClient, /*ShouldOwnClient=*/false));

  if (outputDir.empty()) {

    origCI.getLangOpts()->ObjCAutoRefCount = true;

    return migration.getRemapper().overwriteOriginal(*Diags);

  } else {

    return migration.getRemapper().flushToDisk(outputDir, *Diags);

  }

}

bool arcmt::applyTransformations(

    CompilerInvocation &origCI, const FrontendInputFile &Input,

    std::shared_ptr<PCHContainerOperations> PCHContainerOps,

    DiagnosticConsumer *DiagClient) {

  return applyTransforms(origCI, Input, PCHContainerOps, DiagClient,

                         StringRef(), false, StringRef());

}

bool arcmt::migrateWithTemporaryFiles(

    CompilerInvocation &origCI, const FrontendInputFile &Input,

    std::shared_ptr<PCHContainerOperations> PCHContainerOps,

    DiagnosticConsumer *DiagClient, StringRef outputDir,

    bool emitPremigrationARCErrors, StringRef plistOut) {

  assert(!outputDir.empty() && "Expected output directory path");

  return applyTransforms(origCI, Input, PCHContainerOps, DiagClient, outputDir,

                         emitPremigrationARCErrors, plistOut);

}

bool arcmt::getFileRemappings(std::vector<std::pair<std::string,std::string> > &

                                  remap,

                              StringRef outputDir,

                              DiagnosticConsumer *DiagClient) {

  assert(!outputDir.empty());

  IntrusiveRefCntPtr<DiagnosticIDs> DiagID(new DiagnosticIDs());

  IntrusiveRefCntPtr<DiagnosticsEngine> Diags(

      new DiagnosticsEngine(DiagID, new DiagnosticOptions,

                            DiagClient, /*ShouldOwnClient=*/false));

  FileRemapper remapper;

  bool err = remapper.initFromDisk(outputDir, *Diags,

                                   /*ignoreIfFilesChanged=*/true);

  if (err)

    return true;

  remapper.forEachMapping(

      [&](StringRef From, StringRef To) {

        remap.push_back(std::make_pair(From.str(), To.str()));

      },

      [](StringRef, const llvm::MemoryBufferRef &) 
{}0
);

  return false;

}

//===----------------------------------------------------------------------===//

// CollectTransformActions.

//===----------------------------------------------------------------------===//

namespace {

class ARCMTMacroTrackerPPCallbacks : public PPCallbacks {

  std::vector<SourceLocation> &ARCMTMacroLocs;

public:

  ARCMTMacroTrackerPPCallbacks(std::vector<SourceLocation> &ARCMTMacroLocs)

    : ARCMTMacroLocs(ARCMTMacroLocs) { }

  void MacroExpands(const Token &MacroNameTok, const MacroDefinition &MD,

                    SourceRange Range, const MacroArgs *Args) override {

    if (MacroNameTok.getIdentifierInfo()->getName() == getARCMTMacroName())

      ARCMTMacroLocs.push_back(MacroNameTok.getLocation());

  }

};

class ARCMTMacroTrackerAction : public ASTFrontendAction {

  std::vector<SourceLocation> &ARCMTMacroLocs;

public:

  ARCMTMacroTrackerAction(std::vector<SourceLocation> &ARCMTMacroLocs)

    : ARCMTMacroLocs(ARCMTMacroLocs) { }

  std::unique_ptr<ASTConsumer> CreateASTConsumer(CompilerInstance &CI,

                                                 StringRef InFile) override {

    CI.getPreprocessor().addPPCallbacks(

               std::make_unique<ARCMTMacroTrackerPPCallbacks>(ARCMTMacroLocs));

    return std::make_unique<ASTConsumer>();

  }

};

class RewritesApplicator : public TransformActions::RewriteReceiver {

  Rewriter &rewriter;

  MigrationProcess::RewriteListener *Listener;

public:

  RewritesApplicator(Rewriter &rewriter, ASTContext &ctx,

                     MigrationProcess::RewriteListener *listener)

    : rewriter(rewriter), Listener(listener) {

    if (Listener)

      Listener->start(ctx);

  }

  ~RewritesApplicator() override {

    if (Listener)

      Listener->finish();

  }

  void insert(SourceLocation loc, StringRef text) override {

    bool err = rewriter.InsertText(loc, text, /*InsertAfter=*/true,

                                   /*indentNewLines=*/true);

    if (!err && Listener)

      Listener->insert(loc, text);

  }

  void remove(CharSourceRange range) override {

    Rewriter::RewriteOptions removeOpts;

    removeOpts.IncludeInsertsAtBeginOfRange = false;

    removeOpts.IncludeInsertsAtEndOfRange = false;

    removeOpts.RemoveLineIfEmpty = true;

    bool err = rewriter.RemoveText(range, removeOpts);

    if (!err && Listener)

      Listener->remove(range);

  }

  void increaseIndentation(CharSourceRange range,

                            SourceLocation parentIndent) override {

    rewriter.IncreaseIndentation(range, parentIndent);

  }

};

} // end anonymous namespace.

/// Anchor for VTable.

MigrationProcess::RewriteListener::~RewriteListener() { }

MigrationProcess::MigrationProcess(

    const CompilerInvocation &CI,

    std::shared_ptr<PCHContainerOperations> PCHContainerOps,

    DiagnosticConsumer *diagClient, StringRef outputDir)

    : OrigCI(CI), PCHContainerOps(std::move(PCHContainerOps)),

      DiagClient(diagClient), HadARCErrors(false) {

  if (!outputDir.empty()) {

    IntrusiveRefCntPtr<DiagnosticIDs> DiagID(new DiagnosticIDs());

    IntrusiveRefCntPtr<DiagnosticsEngine> Diags(

      new DiagnosticsEngine(DiagID, &CI.getDiagnosticOpts(),

                            DiagClient, /*ShouldOwnClient=*/false));

    Remapper.initFromDisk(outputDir, *Diags, /*ignoreIfFilesChanged=*/true);

  }

}

bool MigrationProcess::applyTransform(TransformFn trans,

                                      RewriteListener *listener) {

  std::unique_ptr<CompilerInvocation> CInvok;

  CInvok.reset(

      createInvocationForMigration(OrigCI, PCHContainerOps->getRawReader()));

  CInvok->getDiagnosticOpts().IgnoreWarnings = true;

  Remapper.applyMappings(CInvok->getPreprocessorOpts());

  CapturedDiagList capturedDiags;

  std::vector<SourceLocation> ARCMTMacroLocs;

  assert(DiagClient);

  IntrusiveRefCntPtr<DiagnosticIDs> DiagID(new DiagnosticIDs());

  IntrusiveRefCntPtr<DiagnosticsEngine> Diags(

      new DiagnosticsEngine(DiagID, new DiagnosticOptions,

                            DiagClient, /*ShouldOwnClient=*/false));

  // Filter of all diagnostics.

  CaptureDiagnosticConsumer errRec(*Diags, *DiagClient, capturedDiags);

  Diags->setClient(&errRec, /*ShouldOwnClient=*/false);

  std::unique_ptr<ARCMTMacroTrackerAction> ASTAction;

  ASTAction.reset(new ARCMTMacroTrackerAction(ARCMTMacroLocs));

  std::unique_ptr<ASTUnit> Unit(ASTUnit::LoadFromCompilerInvocationAction(

      std::move(CInvok), PCHContainerOps, Diags, ASTAction.get()));

  if (!Unit) {

    errRec.FinishCapture();

    return true;

  }

  Unit->setOwnsRemappedFileBuffers(false); // FileRemapper manages that.

  HadARCErrors = HadARCErrors || 
capturedDiags.hasErrors()38
;

  // Don't filter diagnostics anymore.

  Diags->setClient(DiagClient, /*ShouldOwnClient=*/false);

  ASTContext &Ctx = Unit->getASTContext();

  if (Diags->hasFatalErrorOccurred()) {

    Diags->Reset();

    DiagClient->BeginSourceFile(Ctx.getLangOpts(), &Unit->getPreprocessor());

    capturedDiags.reportDiagnostics(*Diags);

    DiagClient->EndSourceFile();

    errRec.FinishCapture();

    return true;

  }

  // After parsing of source files ended, we want to reuse the

  // diagnostics objects to emit further diagnostics.

  // We call BeginSourceFile because DiagnosticConsumer requires that

  // diagnostics with source range information are emitted only in between

  // BeginSourceFile() and EndSourceFile().

  DiagClient->BeginSourceFile(Ctx.getLangOpts(), &Unit->getPreprocessor());

  Rewriter rewriter(Ctx.getSourceManager(), Ctx.getLangOpts());

  TransformActions TA(*Diags, capturedDiags, Ctx, Unit->getPreprocessor());

  MigrationPass pass(Ctx, OrigCI.getLangOpts()->getGC(),

                     Unit->getSema(), TA, capturedDiags, ARCMTMacroLocs);

  trans(pass);

  {

    RewritesApplicator applicator(rewriter, Ctx, listener);

    TA.applyRewrites(applicator);

  }

  DiagClient->EndSourceFile();

  errRec.FinishCapture();

  if (DiagClient->getNumErrors())

    return true;

  for (Rewriter::buffer_iterator

        I = rewriter.buffer_begin(), E = rewriter.buffer_end(); I != E; 
++I77
) {

    FileID FID = I->first;

    RewriteBuffer &buf = I->second;

    const FileEntry *file = Ctx.getSourceManager().getFileEntryForID(FID);

    assert(file);

    std::string newFname = std::string(file->getName());

    newFname += "-trans";

    SmallString<512> newText;

    llvm::raw_svector_ostream vecOS(newText);

    buf.write(vecOS);

    std::unique_ptr<llvm::MemoryBuffer> memBuf(

        llvm::MemoryBuffer::getMemBufferCopy(

            StringRef(newText.data(), newText.size()), newFname));

    SmallString<64> filePath(file->getName());

    Unit->getFileManager().FixupRelativePath(filePath);

    Remapper.remap(filePath.str(), std::move(memBuf));

  }

  return false;

}