[arcmt] Introduce new '-ccc-arcmt-migrate <path>' ARC migration drive…

…r 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

include/clang-c/ARCMigrate.h

@@ -0,0 +1,79 @@
+/*===-- clang-c/ARCMigrate.h - ARC Migration Public C Interface ---*- C -*-===*\
+|*                                                                            *|
+|*                     The LLVM Compiler Infrastructure                       *|
+|*                                                                            *|
+|* This file is distributed under the University of Illinois Open Source      *|
+|* License. See LICENSE.TXT for details.                                      *|
+|*                                                                            *|
+|*===----------------------------------------------------------------------===*|
+|*                                                                            *|
+|* This header provides a public interface to a Clang library for migrating   *|
+|* objective-c source files to ARC mode.                                      *|
+|*                                                                            *|
+\*===----------------------------------------------------------------------===*/
+
+#ifndef CLANG_C_ARCMIGRATE_H
+#define CLANG_C_ARCMIGRATE_H
+
+#include "clang-c/Index.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** \defgroup CARCMT libclang: C Interface to Clang ARC migration library
+ *
+ * The C Interface provides a small API that exposes facilities for translating
+ * objective-c source files of a project to Automatic Reference Counting mode.
+ *
+ * To avoid namespace pollution, data types are prefixed with "CMT" and
+ * functions are prefixed with "arcmt_".
+ *
+ * @{
+ */
+
+/**
+ * \brief A remapping of original source files and their translated files.
+ */
+typedef void *CMTRemap;
+
+/**
+ * \brief Retrieve a remapping.
+ *
+ * \param migrate_dir_path the path that clang used during the migration process.
+ *
+ * \returns the requested remapping. This remapping must be freed
+ * via a call to \c arcmt_remap_dispose(). Can return NULL if an error occurred.
+ */
+CINDEX_LINKAGE CMTRemap arcmt_getRemappings(const char *migrate_dir_path);
+
+/**
+ * \brief Determine the number of remappings.
+ */
+CINDEX_LINKAGE unsigned arcmt_remap_getNumFiles(CMTRemap);
+
+/**
+ * \brief Get the original filename.
+ */
+CINDEX_LINKAGE CXString arcmt_remap_getOriginalFile(CMTRemap, unsigned index);
+
+/**
+ * \brief Get the filename that the original file was translated into.
+ */
+CINDEX_LINKAGE
+CXString arcmt_remap_getTransformedFile(CMTRemap, unsigned index);
+
+/**
+ * \brief Dispose the remapping.
+ */
+CINDEX_LINKAGE void arcmt_remap_dispose(CMTRemap);
+
+/**
+ * @}
+ */
+
+#ifdef __cplusplus
+}
+#endif
+#endif
+

include/clang/ARCMigrate/ARCMT.h

@@ -41,6 +41,23 @@ bool applyTransformations(CompilerInvocation &origCI,
                           llvm::StringRef Filename, InputKind Kind,
                           DiagnosticClient *DiagClient);
 
+/// \brief Applies automatic modifications and produces temporary files
+/// and metadata into the \arg outputDir path.
+///
+/// \returns false if no error is produced, true otherwise.
+bool migrateWithTemporaryFiles(CompilerInvocation &origCI,
+                               llvm::StringRef Filename, InputKind Kind,
+                               DiagnosticClient *DiagClient,
+                               llvm::StringRef outputDir);
+
+/// \brief Get the set of file remappings from the \arg outputDir path that
+/// migrateWithTemporaryFiles produced.
+///
+/// \returns false if no error is produced, true otherwise.
+bool getFileRemappings(std::vector<std::pair<std::string,std::string> > &remap,
+                       llvm::StringRef outputDir,
+                       DiagnosticClient *DiagClient);
+
 typedef void (*TransformFn)(MigrationPass &pass);
 
 std::vector<TransformFn> getAllTransformations();
@@ -51,8 +68,8 @@ class MigrationProcess {
   FileRemapper Remapper;
 
 public:
-  MigrationProcess(const CompilerInvocation &CI, DiagnosticClient *diagClient)
-    : OrigCI(CI), DiagClient(diagClient) { }
+  MigrationProcess(const CompilerInvocation &CI, DiagnosticClient *diagClient,
+                   llvm::StringRef outputDir = llvm::StringRef());
 
   class RewriteListener {
   public:

include/clang/ARCMigrate/ARCMTActions.h

@@ -24,12 +24,21 @@ class CheckAction : public WrapperFrontendAction {
   CheckAction(FrontendAction *WrappedAction);
 };
 
-class TransformationAction : public WrapperFrontendAction {
+class ModifyAction : public WrapperFrontendAction {
 protected:
   virtual bool BeginInvocation(CompilerInstance &CI);
 
 public:
-  TransformationAction(FrontendAction *WrappedAction);
+  ModifyAction(FrontendAction *WrappedAction);
+};
+
+class MigrateAction : public WrapperFrontendAction {
+  std::string MigrateDir;
+protected:
+  virtual bool BeginInvocation(CompilerInstance &CI);
+
+public:
+  MigrateAction(FrontendAction *WrappedAction, llvm::StringRef migrateDir);
 };
 
 }

include/clang/Driver/CC1Options.td

@@ -389,6 +389,10 @@ def arcmt_check : Flag<"-arcmt-check">,
   HelpText<"Check for ARC migration issues that need manual handling">;
 def arcmt_modify : Flag<"-arcmt-modify">,
   HelpText<"Apply modifications to files to conform to ARC">;
+def arcmt_migrate : Flag<"-arcmt-migrate">,
+  HelpText<"Apply modifications and produces temporary files that conform to ARC">;
+def arcmt_migrate_directory : Separate<"-arcmt-migrate-directory">,
+  HelpText<"Directory for temporary files produced during ARC migration">;
 
 def import_module : Separate<"-import-module">,
   HelpText<"Import a module definition file">;

include/clang/Driver/Options.td

@@ -118,6 +118,10 @@ def ccc_arcmt_modify : Flag<"-ccc-arcmt-modify">, CCCDriverOpt,
   HelpText<"Apply modifications to files to conform to ARC">;
 def ccc_arrmt_check : Flag<"-ccc-arrmt-check">, Alias<ccc_arcmt_check>;
 def ccc_arrmt_modify : Flag<"-ccc-arrmt-modify">, Alias<ccc_arcmt_modify>;
+def ccc_arcmt_migrate : Separate<"-ccc-arcmt-migrate">, CCCDriverOpt,
+  HelpText<"Apply modifications and produces temporary files that conform to ARC">;
+def ccc_arcmt_migrate_EQ : Joined<"-ccc-arcmt-migrate=">, CCCDriverOpt,
+  Alias<ccc_arcmt_migrate>;
 
 // Make sure all other -ccc- options are rejected.
 def ccc_ : Joined<"-ccc-">, Group<ccc_Group>, Flags<[Unsupported]>;

include/clang/Frontend/FrontendOptions.h

@@ -79,9 +79,12 @@ class FrontendOptions {
   enum {
     ARCMT_None,
     ARCMT_Check,
-    ARCMT_Modify
+    ARCMT_Modify,
+    ARCMT_Migrate
   } ARCMTAction;
 
+  std::string ARCMTMigrateDir;
+
   /// The input files and their types.
   std::vector<std::pair<InputKind, std::string> > Inputs;
 

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 @@ class RewritesApplicator : public TransformActions::RewriteReceiver {
 /// \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;

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.
+}

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) {
@@ -115,20 +112,23 @@ 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);
 
   for (MappingsTy::iterator
          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;

lib/Driver/Tools.cpp

@@ -1423,7 +1423,8 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
 
   if (!Args.hasArg(options::OPT_fno_objc_arc)) {
     if (const Arg *A = Args.getLastArg(options::OPT_ccc_arcmt_check,
-                                       options::OPT_ccc_arcmt_modify)) {
+                                       options::OPT_ccc_arcmt_modify,
+                                       options::OPT_ccc_arcmt_migrate)) {
       switch (A->getOption().getID()) {
       default:
         llvm_unreachable("missed a case");
@@ -1433,6 +1434,11 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
       case options::OPT_ccc_arcmt_modify:
         CmdArgs.push_back("-arcmt-modify");
         break;
+      case options::OPT_ccc_arcmt_migrate:
+        CmdArgs.push_back("-arcmt-migrate");
+        CmdArgs.push_back("-arcmt-migrate-directory");
+        CmdArgs.push_back(A->getValue(Args));
+        break;
       }
     }
   }