[arcmt] Introduce new '-ccc-arcmt-migrate <path>' ARC migration driver option.

This is a new mode of migration, where we avoid modifying the original files but
we emit temporary files instead.

<path> will be used to keep migration process metadata. Currently the temporary files
that are produced are put in the system's temp directory but we can put them
in the <path> if is necessary.

Also introduce new ARC migration functions in libclang whose only purpose,
currently, is to accept <path> and provide pairs of original file/transformed file
to map from the originals to the files after transformations are applied.

Finally introduce the c-arcmt-test utility that exercises the new libclang functions,
update arcmt-test, and add tests for the whole process.

rdar://9735086.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@134844 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 87 insertions, 19 deletions

diff --git a/lib/ARCMigrate/ARCMT.cpp b/lib/ARCMigrate/ARCMT.cpp
index 0678a255d7..73c8dbd6a4 100644
--- a/lib/ARCMigrate/ARCMT.cpp
+++ b/lib/ARCMigrate/ARCMT.cpp
@@ -269,9 +269,10 @@ bool arcmt::checkForManualIssues(CompilerInvocation &origCI,
 // applyTransformations.
 //===----------------------------------------------------------------------===//
 
-bool arcmt::applyTransformations(CompilerInvocation &origCI,
-                                 llvm::StringRef Filename, InputKind Kind,
-                                 DiagnosticClient *DiagClient) {
+static bool applyTransforms(CompilerInvocation &origCI,
+                            llvm::StringRef Filename, InputKind Kind,
+                            DiagnosticClient *DiagClient,
+                            llvm::StringRef outputDir) {
   if (!origCI.getLangOpts().ObjC1)
     return false;
 
@@ -284,7 +285,7 @@ bool arcmt::applyTransformations(CompilerInvocation &origCI,
   CInvok.getFrontendOpts().Inputs.clear();
   CInvok.getFrontendOpts().Inputs.push_back(std::make_pair(Kind, Filename));
   
-  MigrationProcess migration(CInvok, DiagClient);
+  MigrationProcess migration(CInvok, DiagClient, outputDir);
 
   std::vector<TransformFn> transforms = arcmt::getAllTransformations();
   assert(!transforms.empty());
@@ -294,12 +295,52 @@ bool arcmt::applyTransformations(CompilerInvocation &origCI,
     if (err) return true;
   }
 
-  origCI.getLangOpts().ObjCAutoRefCount = true;
+  llvm::IntrusiveRefCntPtr<DiagnosticIDs> DiagID(new DiagnosticIDs());
+  llvm::IntrusiveRefCntPtr<Diagnostic> Diags(
+                 new Diagnostic(DiagID, 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,
+                                 llvm::StringRef Filename, InputKind Kind,
+                                 DiagnosticClient *DiagClient) {
+  return applyTransforms(origCI, Filename, Kind, DiagClient, llvm::StringRef());
+}
+
+bool arcmt::migrateWithTemporaryFiles(CompilerInvocation &origCI,
+                                      llvm::StringRef Filename, InputKind Kind,
+                                      DiagnosticClient *DiagClient,
+                                      llvm::StringRef outputDir) {
+  assert(!outputDir.empty() && "Expected output directory path");
+  return applyTransforms(origCI, Filename, Kind, DiagClient, outputDir);
+}
+
+bool arcmt::getFileRemappings(std::vector<std::pair<std::string,std::string> > &
+                                  remap,
+                              llvm::StringRef outputDir,
+                              DiagnosticClient *DiagClient) {
+  assert(!outputDir.empty());
 
   llvm::IntrusiveRefCntPtr<DiagnosticIDs> DiagID(new DiagnosticIDs());
   llvm::IntrusiveRefCntPtr<Diagnostic> Diags(
                  new Diagnostic(DiagID, DiagClient, /*ShouldOwnClient=*/false));
-  return migration.getRemapper().overwriteOriginal(*Diags);
+
+  FileRemapper remapper;
+  bool err = remapper.initFromDisk(outputDir, *Diags,
+                                   /*ignoreIfFilesChanged=*/true);
+  if (err)
+    return true;
+
+  CompilerInvocation CI;
+  remapper.applyMappings(CI);
+  remap = CI.getPreprocessorOpts().RemappedFiles;
+
+  return false;
 }
 
 //===----------------------------------------------------------------------===//
@@ -382,6 +423,18 @@ public:
 /// \brief Anchor for VTable.
 MigrationProcess::RewriteListener::~RewriteListener() { }
 
+MigrationProcess::MigrationProcess(const CompilerInvocation &CI,
+                                   DiagnosticClient *diagClient,
+                                   llvm::StringRef outputDir)
+  : OrigCI(CI), DiagClient(diagClient) {
+  if (!outputDir.empty()) {
+    llvm::IntrusiveRefCntPtr<DiagnosticIDs> DiagID(new DiagnosticIDs());
+    llvm::IntrusiveRefCntPtr<Diagnostic> Diags(
+                 new Diagnostic(DiagID, DiagClient, /*ShouldOwnClient=*/false));
+    Remapper.initFromDisk(outputDir, *Diags, /*ignoreIfFilesChanges=*/true);
+  }
+}
+
 bool MigrationProcess::applyTransform(TransformFn trans,
                                       RewriteListener *listener) {
   llvm::OwningPtr<CompilerInvocation> CInvok;
diff --git a/lib/ARCMigrate/ARCMTActions.cpp b/lib/ARCMigrate/ARCMTActions.cpp
index 7de62d289c..345c745242 100644
--- a/lib/ARCMigrate/ARCMTActions.cpp
+++ b/lib/ARCMigrate/ARCMTActions.cpp
@@ -28,11 +28,26 @@ bool CheckAction::BeginInvocation(CompilerInstance &CI) {
 CheckAction::CheckAction(FrontendAction *WrappedAction)
   : WrapperFrontendAction(WrappedAction) {}
 
-bool TransformationAction::BeginInvocation(CompilerInstance &CI) {
-  return !arcmt::applyTransformations(CI.getInvocation(), getCurrentFile(),
-                                  getCurrentFileKind(),
-                                  CI.getDiagnostics().getClient());
+bool ModifyAction::BeginInvocation(CompilerInstance &CI) {
+  return !arcmt::applyTransformations(CI.getInvocation(),
+                                      getCurrentFile(), getCurrentFileKind(),
+                                      CI.getDiagnostics().getClient());
 }
 
-TransformationAction::TransformationAction(FrontendAction *WrappedAction)
+ModifyAction::ModifyAction(FrontendAction *WrappedAction)
   : WrapperFrontendAction(WrappedAction) {}
+
+bool MigrateAction::BeginInvocation(CompilerInstance &CI) {
+  return !arcmt::migrateWithTemporaryFiles(CI.getInvocation(),
+                                           getCurrentFile(),
+                                           getCurrentFileKind(),
+                                           CI.getDiagnostics().getClient(),
+                                           MigrateDir);
+}
+
+MigrateAction::MigrateAction(FrontendAction *WrappedAction,
+                             llvm::StringRef migrateDir)
+  : WrapperFrontendAction(WrappedAction), MigrateDir(migrateDir) {
+  if (MigrateDir.empty())
+    MigrateDir = "."; // user current directory if none is given.
+}
diff --git a/lib/ARCMigrate/FileRemapper.cpp b/lib/ARCMigrate/FileRemapper.cpp
index ae5d3a3c93..c1dbe92ffb 100644
--- a/lib/ARCMigrate/FileRemapper.cpp
+++ b/lib/ARCMigrate/FileRemapper.cpp
@@ -71,11 +71,8 @@ bool FileRemapper::initFromDisk(llvm::StringRef outputDir, Diagnostic &Diag,
     fin >> fromFilename >> timeModified >> toFilename;
     if (fin.eof())
       break;
-    if (!fin.good()) {
-      if (ignoreIfFilesChanged)
-        return false;
+    if (!fin.good())
       return report(std::string("Error in format of file: ") + infoFile, Diag);
-    }
 
     const FileEntry *origFE = FileMgr->getFile(fromFilename);
     if (!origFE) {
@@ -115,8 +112,7 @@ bool FileRemapper::flushToDisk(llvm::StringRef outputDir, Diagnostic &Diag) {
 
   std::string errMsg;
   std::string infoFile = getRemapInfoFile(outputDir);
-  llvm::raw_fd_ostream infoOut(infoFile.c_str(), errMsg,
-                               llvm::raw_fd_ostream::F_Binary);
+  llvm::raw_fd_ostream infoOut(infoFile.c_str(), errMsg);
   if (!errMsg.empty() || infoOut.has_error())
     return report(errMsg, Diag);
 
@@ -124,11 +120,15 @@ bool FileRemapper::flushToDisk(llvm::StringRef outputDir, Diagnostic &Diag) {
          I = FromToMappings.begin(), E = FromToMappings.end(); I != E; ++I) {
 
     const FileEntry *origFE = I->first;
-    infoOut << origFE->getName() << '\n';
+    llvm::SmallString<200> origPath = llvm::StringRef(origFE->getName());
+    fs::make_absolute(origPath);
+    infoOut << origPath << '\n';
     infoOut << (uint64_t)origFE->getModificationTime() << '\n';
 
     if (const FileEntry *FE = I->second.dyn_cast<const FileEntry *>()) {
-      infoOut << FE->getName() << '\n';
+      llvm::SmallString<200> newPath = llvm::StringRef(FE->getName());
+      fs::make_absolute(newPath);
+      infoOut << newPath << '\n';
     } else {
 
       llvm::SmallString<64> tempPath;