ARCMT.cpp revision 6f42b62b6194f53bcbc349f5d17388e1936535d7 
1//===--- ARCMT.cpp - Migration to ARC mode --------------------------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9
10#include "Internals.h"
11#include "clang/Frontend/ASTUnit.h"
12#include "clang/Frontend/CompilerInstance.h"
13#include "clang/Frontend/FrontendAction.h"
14#include "clang/Frontend/TextDiagnosticPrinter.h"
15#include "clang/Frontend/Utils.h"
16#include "clang/AST/ASTConsumer.h"
17#include "clang/Rewrite/Rewriter.h"
18#include "clang/Sema/SemaDiagnostic.h"
19#include "clang/Basic/DiagnosticCategories.h"
20#include "clang/Lex/Preprocessor.h"
21#include "llvm/Support/MemoryBuffer.h"
22#include "llvm/ADT/Triple.h"
23using namespace clang;
24using namespace arcmt;
25
26bool CapturedDiagList::clearDiagnostic(ArrayRef<unsigned> IDs,
27                                       SourceRange range) {
28  if (range.isInvalid())
29    return false;
30
31  bool cleared = false;
32  ListTy::iterator I = List.begin();
33  while (I != List.end()) {
34    FullSourceLoc diagLoc = I->getLocation();
35    if ((IDs.empty() || // empty means clear all diagnostics in the range.
36         std::find(IDs.begin(), IDs.end(), I->getID()) != IDs.end()) &&
37        !diagLoc.isBeforeInTranslationUnitThan(range.getBegin()) &&
38        (diagLoc == range.getEnd() ||
39           diagLoc.isBeforeInTranslationUnitThan(range.getEnd()))) {
40      cleared = true;
41      ListTy::iterator eraseS = I++;
42      while (I != List.end() && I->getLevel() == DiagnosticsEngine::Note)
43        ++I;
44      // Clear the diagnostic and any notes following it.
45      List.erase(eraseS, I);
46      continue;
47    }
48
49    ++I;
50  }
51
52  return cleared;
53}
54
55bool CapturedDiagList::hasDiagnostic(ArrayRef<unsigned> IDs,
56                                     SourceRange range) const {
57  if (range.isInvalid())
58    return false;
59
60  ListTy::const_iterator I = List.begin();
61  while (I != List.end()) {
62    FullSourceLoc diagLoc = I->getLocation();
63    if ((IDs.empty() || // empty means any diagnostic in the range.
64         std::find(IDs.begin(), IDs.end(), I->getID()) != IDs.end()) &&
65        !diagLoc.isBeforeInTranslationUnitThan(range.getBegin()) &&
66        (diagLoc == range.getEnd() ||
67           diagLoc.isBeforeInTranslationUnitThan(range.getEnd()))) {
68      return true;
69    }
70
71    ++I;
72  }
73
74  return false;
75}
76
77void CapturedDiagList::reportDiagnostics(DiagnosticsEngine &Diags) const {
78  for (ListTy::const_iterator I = List.begin(), E = List.end(); I != E; ++I)
79    Diags.Report(*I);
80}
81
82bool CapturedDiagList::hasErrors() const {
83  for (ListTy::const_iterator I = List.begin(), E = List.end(); I != E; ++I)
84    if (I->getLevel() >= DiagnosticsEngine::Error)
85      return true;
86
87  return false;
88}
89
90namespace {
91
92class CaptureDiagnosticConsumer : public DiagnosticConsumer {
93  DiagnosticsEngine &Diags;
94  CapturedDiagList &CapturedDiags;
95public:
96  CaptureDiagnosticConsumer(DiagnosticsEngine &diags,
97                           CapturedDiagList &capturedDiags)
98    : Diags(diags), CapturedDiags(capturedDiags) { }
99
100  virtual void HandleDiagnostic(DiagnosticsEngine::Level level,
101                                const Diagnostic &Info) {
102    if (DiagnosticIDs::isARCDiagnostic(Info.getID()) ||
103        level >= DiagnosticsEngine::Error || level == DiagnosticsEngine::Note) {
104      CapturedDiags.push_back(StoredDiagnostic(level, Info));
105      return;
106    }
107
108    // Non-ARC warnings are ignored.
109    Diags.setLastDiagnosticIgnored();
110  }
111
112  DiagnosticConsumer *clone(DiagnosticsEngine &Diags) const {
113    // Just drop any diagnostics that come from cloned consumers; they'll
114    // have different source managers anyway.
115    return new IgnoringDiagConsumer();
116  }
117};
118
119} // end anonymous namespace
120
121static inline StringRef SimulatorVersionDefineName() {
122  return "__IPHONE_OS_VERSION_MIN_REQUIRED=";
123}
124
125/// \brief Parse the simulator version define:
126/// __IPHONE_OS_VERSION_MIN_REQUIRED=([0-9])([0-9][0-9])([0-9][0-9])
127// and return the grouped values as integers, e.g:
128//   __IPHONE_OS_VERSION_MIN_REQUIRED=40201
129// will return Major=4, Minor=2, Micro=1.
130static bool GetVersionFromSimulatorDefine(StringRef define,
131                                          unsigned &Major, unsigned &Minor,
132                                          unsigned &Micro) {
133  assert(define.startswith(SimulatorVersionDefineName()));
134  StringRef name, version;
135  llvm::tie(name, version) = define.split('=');
136  if (version.empty())
137    return false;
138  std::string verstr = version.str();
139  char *end;
140  unsigned num = (unsigned) strtol(verstr.c_str(), &end, 10);
141  if (*end != '\0')
142    return false;
143  Major = num / 10000;
144  num = num % 10000;
145  Minor = num / 100;
146  Micro = num % 100;
147  return true;
148}
149
150static bool HasARCRuntime(CompilerInvocation &origCI) {
151  // This duplicates some functionality from Darwin::AddDeploymentTarget
152  // but this function is well defined, so keep it decoupled from the driver
153  // and avoid unrelated complications.
154
155  for (unsigned i = 0, e = origCI.getPreprocessorOpts().Macros.size();
156         i != e; ++i) {
157    StringRef define = origCI.getPreprocessorOpts().Macros[i].first;
158    bool isUndef = origCI.getPreprocessorOpts().Macros[i].second;
159    if (isUndef)
160      continue;
161    if (!define.startswith(SimulatorVersionDefineName()))
162      continue;
163    unsigned Major = 0, Minor = 0, Micro = 0;
164    if (GetVersionFromSimulatorDefine(define, Major, Minor, Micro) &&
165        Major < 10 && Minor < 100 && Micro < 100)
166      return Major >= 5;
167  }
168
169  llvm::Triple triple(origCI.getTargetOpts().Triple);
170
171  if (triple.getOS() == llvm::Triple::IOS)
172    return triple.getOSMajorVersion() >= 5;
173
174  if (triple.getOS() == llvm::Triple::Darwin)
175    return triple.getOSMajorVersion() >= 11;
176
177  if (triple.getOS() == llvm::Triple::MacOSX) {
178    unsigned Major, Minor, Micro;
179    triple.getOSVersion(Major, Minor, Micro);
180    return Major > 10 || (Major == 10 && Minor >= 7);
181  }
182
183  return false;
184}
185
186static CompilerInvocation *
187createInvocationForMigration(CompilerInvocation &origCI) {
188  OwningPtr<CompilerInvocation> CInvok;
189  CInvok.reset(new CompilerInvocation(origCI));
190  CInvok->getPreprocessorOpts().ImplicitPCHInclude = std::string();
191  CInvok->getPreprocessorOpts().ImplicitPTHInclude = std::string();
192  std::string define = getARCMTMacroName();
193  define += '=';
194  CInvok->getPreprocessorOpts().addMacroDef(define);
195  CInvok->getLangOpts()->ObjCAutoRefCount = true;
196  CInvok->getLangOpts()->setGC(LangOptions::NonGC);
197  CInvok->getDiagnosticOpts().ErrorLimit = 0;
198  CInvok->getDiagnosticOpts().Warnings.push_back(
199                                            "error=arc-unsafe-retained-assign");
200  CInvok->getLangOpts()->ObjCRuntimeHasWeak = HasARCRuntime(origCI);
201
202  return CInvok.take();
203}
204
205static void emitPremigrationErrors(const CapturedDiagList &arcDiags,
206                                   const DiagnosticOptions &diagOpts,
207                                   Preprocessor &PP) {
208  TextDiagnosticPrinter printer(llvm::errs(), diagOpts);
209  llvm::IntrusiveRefCntPtr<DiagnosticIDs> DiagID(new DiagnosticIDs());
210  llvm::IntrusiveRefCntPtr<DiagnosticsEngine> Diags(
211      new DiagnosticsEngine(DiagID, &printer, /*ShouldOwnClient=*/false));
212  Diags->setSourceManager(&PP.getSourceManager());
213
214  printer.BeginSourceFile(PP.getLangOptions(), &PP);
215  arcDiags.reportDiagnostics(*Diags);
216  printer.EndSourceFile();
217}
218
219//===----------------------------------------------------------------------===//
220// checkForManualIssues.
221//===----------------------------------------------------------------------===//
222
223bool arcmt::checkForManualIssues(CompilerInvocation &origCI,
224                                 const FrontendInputFile &Input,
225                                 DiagnosticConsumer *DiagClient,
226                                 bool emitPremigrationARCErrors,
227                                 StringRef plistOut) {
228  if (!origCI.getLangOpts()->ObjC1)
229    return false;
230
231  LangOptions::GCMode OrigGCMode = origCI.getLangOpts()->getGC();
232  bool NoNSAllocReallocError = origCI.getMigratorOpts().NoNSAllocReallocError;
233  bool NoFinalizeRemoval = origCI.getMigratorOpts().NoFinalizeRemoval;
234
235  std::vector<TransformFn> transforms = arcmt::getAllTransformations(OrigGCMode,
236                                                                     NoFinalizeRemoval);
237  assert(!transforms.empty());
238
239  OwningPtr<CompilerInvocation> CInvok;
240  CInvok.reset(createInvocationForMigration(origCI));
241  CInvok->getFrontendOpts().Inputs.clear();
242  CInvok->getFrontendOpts().Inputs.push_back(Input);
243
244  CapturedDiagList capturedDiags;
245
246  assert(DiagClient);
247  llvm::IntrusiveRefCntPtr<DiagnosticIDs> DiagID(new DiagnosticIDs());
248  llvm::IntrusiveRefCntPtr<DiagnosticsEngine> Diags(
249      new DiagnosticsEngine(DiagID, DiagClient, /*ShouldOwnClient=*/false));
250
251  // Filter of all diagnostics.
252  CaptureDiagnosticConsumer errRec(*Diags, capturedDiags);
253  Diags->setClient(&errRec, /*ShouldOwnClient=*/false);
254
255  OwningPtr<ASTUnit> Unit(
256      ASTUnit::LoadFromCompilerInvocationAction(CInvok.take(), Diags));
257  if (!Unit)
258    return true;
259
260  // Don't filter diagnostics anymore.
261  Diags->setClient(DiagClient, /*ShouldOwnClient=*/false);
262
263  ASTContext &Ctx = Unit->getASTContext();
264
265  if (Diags->hasFatalErrorOccurred()) {
266    Diags->Reset();
267    DiagClient->BeginSourceFile(Ctx.getLangOptions(), &Unit->getPreprocessor());
268    capturedDiags.reportDiagnostics(*Diags);
269    DiagClient->EndSourceFile();
270    return true;
271  }
272
273  if (emitPremigrationARCErrors)
274    emitPremigrationErrors(capturedDiags, origCI.getDiagnosticOpts(),
275                           Unit->getPreprocessor());
276  if (!plistOut.empty()) {
277    SmallVector<StoredDiagnostic, 8> arcDiags;
278    for (CapturedDiagList::iterator
279           I = capturedDiags.begin(), E = capturedDiags.end(); I != E; ++I)
280      arcDiags.push_back(*I);
281    writeARCDiagsToPlist(plistOut, arcDiags,
282                         Ctx.getSourceManager(), Ctx.getLangOptions());
283  }
284
285  // After parsing of source files ended, we want to reuse the
286  // diagnostics objects to emit further diagnostics.
287  // We call BeginSourceFile because DiagnosticConsumer requires that
288  // diagnostics with source range information are emitted only in between
289  // BeginSourceFile() and EndSourceFile().
290  DiagClient->BeginSourceFile(Ctx.getLangOptions(), &Unit->getPreprocessor());
291
292  // No macros will be added since we are just checking and we won't modify
293  // source code.
294  std::vector<SourceLocation> ARCMTMacroLocs;
295
296  TransformActions testAct(*Diags, capturedDiags, Ctx, Unit->getPreprocessor());
297  MigrationPass pass(Ctx, OrigGCMode, Unit->getSema(), testAct, ARCMTMacroLocs);
298  pass.setNSAllocReallocError(NoNSAllocReallocError);
299  pass.setNoFinalizeRemoval(NoFinalizeRemoval);
300
301  for (unsigned i=0, e = transforms.size(); i != e; ++i)
302    transforms[i](pass);
303
304  capturedDiags.reportDiagnostics(*Diags);
305
306  DiagClient->EndSourceFile();
307
308  // If we are migrating code that gets the '-fobjc-arc' flag, make sure
309  // to remove it so that we don't get errors from normal compilation.
310  origCI.getLangOpts()->ObjCAutoRefCount = false;
311
312  return capturedDiags.hasErrors() || testAct.hasReportedErrors();
313}
314
315//===----------------------------------------------------------------------===//
316// applyTransformations.
317//===----------------------------------------------------------------------===//
318
319static bool applyTransforms(CompilerInvocation &origCI,
320                            const FrontendInputFile &Input,
321                            DiagnosticConsumer *DiagClient,
322                            StringRef outputDir,
323                            bool emitPremigrationARCErrors,
324                            StringRef plistOut) {
325  if (!origCI.getLangOpts()->ObjC1)
326    return false;
327
328  LangOptions::GCMode OrigGCMode = origCI.getLangOpts()->getGC();
329
330  // Make sure checking is successful first.
331  CompilerInvocation CInvokForCheck(origCI);
332  if (arcmt::checkForManualIssues(CInvokForCheck, Input, DiagClient,
333                                  emitPremigrationARCErrors, plistOut))
334    return true;
335
336  CompilerInvocation CInvok(origCI);
337  CInvok.getFrontendOpts().Inputs.clear();
338  CInvok.getFrontendOpts().Inputs.push_back(Input);
339
340  MigrationProcess migration(CInvok, DiagClient, outputDir);
341  bool NoFinalizeRemoval = origCI.getMigratorOpts().NoFinalizeRemoval;
342
343  std::vector<TransformFn> transforms = arcmt::getAllTransformations(OrigGCMode,
344                                                                     NoFinalizeRemoval);
345  assert(!transforms.empty());
346
347  for (unsigned i=0, e = transforms.size(); i != e; ++i) {
348    bool err = migration.applyTransform(transforms[i]);
349    if (err) return true;
350  }
351
352  llvm::IntrusiveRefCntPtr<DiagnosticIDs> DiagID(new DiagnosticIDs());
353  llvm::IntrusiveRefCntPtr<DiagnosticsEngine> Diags(
354      new DiagnosticsEngine(DiagID, DiagClient, /*ShouldOwnClient=*/false));
355
356  if (outputDir.empty()) {
357    origCI.getLangOpts()->ObjCAutoRefCount = true;
358    return migration.getRemapper().overwriteOriginal(*Diags);
359  } else {
360    // If we are migrating code that gets the '-fobjc-arc' flag, make sure
361    // to remove it so that we don't get errors from normal compilation.
362    origCI.getLangOpts()->ObjCAutoRefCount = false;
363    return migration.getRemapper().flushToDisk(outputDir, *Diags);
364  }
365}
366
367bool arcmt::applyTransformations(CompilerInvocation &origCI,
368                                 const FrontendInputFile &Input,
369                                 DiagnosticConsumer *DiagClient) {
370  return applyTransforms(origCI, Input, DiagClient,
371                         StringRef(), false, StringRef());
372}
373
374bool arcmt::migrateWithTemporaryFiles(CompilerInvocation &origCI,
375                                      const FrontendInputFile &Input,
376                                      DiagnosticConsumer *DiagClient,
377                                      StringRef outputDir,
378                                      bool emitPremigrationARCErrors,
379                                      StringRef plistOut) {
380  assert(!outputDir.empty() && "Expected output directory path");
381  return applyTransforms(origCI, Input, DiagClient,
382                         outputDir, emitPremigrationARCErrors, plistOut);
383}
384
385bool arcmt::getFileRemappings(std::vector<std::pair<std::string,std::string> > &
386                                  remap,
387                              StringRef outputDir,
388                              DiagnosticConsumer *DiagClient) {
389  assert(!outputDir.empty());
390
391  llvm::IntrusiveRefCntPtr<DiagnosticIDs> DiagID(new DiagnosticIDs());
392  llvm::IntrusiveRefCntPtr<DiagnosticsEngine> Diags(
393      new DiagnosticsEngine(DiagID, DiagClient, /*ShouldOwnClient=*/false));
394
395  FileRemapper remapper;
396  bool err = remapper.initFromDisk(outputDir, *Diags,
397                                   /*ignoreIfFilesChanged=*/true);
398  if (err)
399    return true;
400
401  CompilerInvocation CI;
402  remapper.applyMappings(CI);
403  remap = CI.getPreprocessorOpts().RemappedFiles;
404
405  return false;
406}
407
408//===----------------------------------------------------------------------===//
409// CollectTransformActions.
410//===----------------------------------------------------------------------===//
411
412namespace {
413
414class ARCMTMacroTrackerPPCallbacks : public PPCallbacks {
415  std::vector<SourceLocation> &ARCMTMacroLocs;
416
417public:
418  ARCMTMacroTrackerPPCallbacks(std::vector<SourceLocation> &ARCMTMacroLocs)
419    : ARCMTMacroLocs(ARCMTMacroLocs) { }
420
421  virtual void MacroExpands(const Token &MacroNameTok, const MacroInfo *MI,
422                            SourceRange Range) {
423    if (MacroNameTok.getIdentifierInfo()->getName() == getARCMTMacroName())
424      ARCMTMacroLocs.push_back(MacroNameTok.getLocation());
425  }
426};
427
428class ARCMTMacroTrackerAction : public ASTFrontendAction {
429  std::vector<SourceLocation> &ARCMTMacroLocs;
430
431public:
432  ARCMTMacroTrackerAction(std::vector<SourceLocation> &ARCMTMacroLocs)
433    : ARCMTMacroLocs(ARCMTMacroLocs) { }
434
435  virtual ASTConsumer *CreateASTConsumer(CompilerInstance &CI,
436                                         StringRef InFile) {
437    CI.getPreprocessor().addPPCallbacks(
438                              new ARCMTMacroTrackerPPCallbacks(ARCMTMacroLocs));
439    return new ASTConsumer();
440  }
441};
442
443class RewritesApplicator : public TransformActions::RewriteReceiver {
444  Rewriter &rewriter;
445  ASTContext &Ctx;
446  MigrationProcess::RewriteListener *Listener;
447
448public:
449  RewritesApplicator(Rewriter &rewriter, ASTContext &ctx,
450                     MigrationProcess::RewriteListener *listener)
451    : rewriter(rewriter), Ctx(ctx), Listener(listener) {
452    if (Listener)
453      Listener->start(ctx);
454  }
455  ~RewritesApplicator() {
456    if (Listener)
457      Listener->finish();
458  }
459
460  virtual void insert(SourceLocation loc, StringRef text) {
461    bool err = rewriter.InsertText(loc, text, /*InsertAfter=*/true,
462                                   /*indentNewLines=*/true);
463    if (!err && Listener)
464      Listener->insert(loc, text);
465  }
466
467  virtual void remove(CharSourceRange range) {
468    Rewriter::RewriteOptions removeOpts;
469    removeOpts.IncludeInsertsAtBeginOfRange = false;
470    removeOpts.IncludeInsertsAtEndOfRange = false;
471    removeOpts.RemoveLineIfEmpty = true;
472
473    bool err = rewriter.RemoveText(range, removeOpts);
474    if (!err && Listener)
475      Listener->remove(range);
476  }
477
478  virtual void increaseIndentation(CharSourceRange range,
479                                    SourceLocation parentIndent) {
480    rewriter.IncreaseIndentation(range, parentIndent);
481  }
482};
483
484} // end anonymous namespace.
485
486/// \brief Anchor for VTable.
487MigrationProcess::RewriteListener::~RewriteListener() { }
488
489MigrationProcess::MigrationProcess(const CompilerInvocation &CI,
490                                   DiagnosticConsumer *diagClient,
491                                   StringRef outputDir)
492  : OrigCI(CI), DiagClient(diagClient) {
493  if (!outputDir.empty()) {
494    llvm::IntrusiveRefCntPtr<DiagnosticIDs> DiagID(new DiagnosticIDs());
495    llvm::IntrusiveRefCntPtr<DiagnosticsEngine> Diags(
496      new DiagnosticsEngine(DiagID, DiagClient, /*ShouldOwnClient=*/false));
497    Remapper.initFromDisk(outputDir, *Diags, /*ignoreIfFilesChanges=*/true);
498  }
499}
500
501bool MigrationProcess::applyTransform(TransformFn trans,
502                                      RewriteListener *listener) {
503  OwningPtr<CompilerInvocation> CInvok;
504  CInvok.reset(createInvocationForMigration(OrigCI));
505  CInvok->getDiagnosticOpts().IgnoreWarnings = true;
506
507  Remapper.applyMappings(*CInvok);
508
509  CapturedDiagList capturedDiags;
510  std::vector<SourceLocation> ARCMTMacroLocs;
511
512  assert(DiagClient);
513  llvm::IntrusiveRefCntPtr<DiagnosticIDs> DiagID(new DiagnosticIDs());
514  llvm::IntrusiveRefCntPtr<DiagnosticsEngine> Diags(
515      new DiagnosticsEngine(DiagID, DiagClient, /*ShouldOwnClient=*/false));
516
517  // Filter of all diagnostics.
518  CaptureDiagnosticConsumer errRec(*Diags, capturedDiags);
519  Diags->setClient(&errRec, /*ShouldOwnClient=*/false);
520
521  OwningPtr<ARCMTMacroTrackerAction> ASTAction;
522  ASTAction.reset(new ARCMTMacroTrackerAction(ARCMTMacroLocs));
523
524  OwningPtr<ASTUnit> Unit(
525      ASTUnit::LoadFromCompilerInvocationAction(CInvok.take(), Diags,
526                                                ASTAction.get()));
527  if (!Unit)
528    return true;
529  Unit->setOwnsRemappedFileBuffers(false); // FileRemapper manages that.
530
531  // Don't filter diagnostics anymore.
532  Diags->setClient(DiagClient, /*ShouldOwnClient=*/false);
533
534  ASTContext &Ctx = Unit->getASTContext();
535
536  if (Diags->hasFatalErrorOccurred()) {
537    Diags->Reset();
538    DiagClient->BeginSourceFile(Ctx.getLangOptions(), &Unit->getPreprocessor());
539    capturedDiags.reportDiagnostics(*Diags);
540    DiagClient->EndSourceFile();
541    return true;
542  }
543
544  // After parsing of source files ended, we want to reuse the
545  // diagnostics objects to emit further diagnostics.
546  // We call BeginSourceFile because DiagnosticConsumer requires that
547  // diagnostics with source range information are emitted only in between
548  // BeginSourceFile() and EndSourceFile().
549  DiagClient->BeginSourceFile(Ctx.getLangOptions(), &Unit->getPreprocessor());
550
551  Rewriter rewriter(Ctx.getSourceManager(), Ctx.getLangOptions());
552  TransformActions TA(*Diags, capturedDiags, Ctx, Unit->getPreprocessor());
553  MigrationPass pass(Ctx, OrigCI.getLangOpts()->getGC(),
554                     Unit->getSema(), TA, ARCMTMacroLocs);
555
556  trans(pass);
557
558  {
559    RewritesApplicator applicator(rewriter, Ctx, listener);
560    TA.applyRewrites(applicator);
561  }
562
563  DiagClient->EndSourceFile();
564
565  if (DiagClient->getNumErrors())
566    return true;
567
568  for (Rewriter::buffer_iterator
569        I = rewriter.buffer_begin(), E = rewriter.buffer_end(); I != E; ++I) {
570    FileID FID = I->first;
571    RewriteBuffer &buf = I->second;
572    const FileEntry *file = Ctx.getSourceManager().getFileEntryForID(FID);
573    assert(file);
574    std::string newFname = file->getName();
575    newFname += "-trans";
576    llvm::SmallString<512> newText;
577    llvm::raw_svector_ostream vecOS(newText);
578    buf.write(vecOS);
579    vecOS.flush();
580    llvm::MemoryBuffer *memBuf = llvm::MemoryBuffer::getMemBufferCopy(
581                   StringRef(newText.data(), newText.size()), newFname);
582    llvm::SmallString<64> filePath(file->getName());
583    Unit->getFileManager().FixupRelativePath(filePath);
584    Remapper.remap(filePath.str(), memBuf);
585  }
586
587  return false;
588}
589