Add new code migrator support for migrating existing Objective-C code to use

the new Objective-C NSArray/NSDictionary/NSNumber literal syntax.

This introduces a new library, libEdit, which provides a new way to support
migration of code that improves on the original ARC migrator.  We now believe
that most of its functionality can be refactored into the existing libraries,
and thus this new library may shortly disappear.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@152141 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 226 insertions, 0 deletions

diff --git a/lib/ARCMigrate/ObjCMT.cpp b/lib/ARCMigrate/ObjCMT.cpp
new file mode 100644
index 0000000000..497377a394
--- /dev/null
+++ b/lib/ARCMigrate/ObjCMT.cpp
@@ -0,0 +1,226 @@
+//===--- ObjCMT.cpp - ObjC Migrate Tool -----------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/ARCMigrate/ARCMTActions.h"
+#include "clang/Frontend/CompilerInstance.h"
+#include "clang/Frontend/MultiplexConsumer.h"
+#include "clang/AST/RecursiveASTVisitor.h"
+#include "clang/AST/NSAPI.h"
+#include "clang/AST/ASTConsumer.h"
+#include "clang/Edit/Rewriters.h"
+#include "clang/Edit/EditedSource.h"
+#include "clang/Edit/Commit.h"
+#include "clang/Edit/EditsReceiver.h"
+#include "clang/Rewrite/Rewriter.h"
+#include "clang/Lex/Preprocessor.h"
+#include "clang/Basic/FileManager.h"
+#include "llvm/ADT/SmallString.h"
+
+using namespace clang;
+using namespace arcmt;
+
+namespace {
+
+class ObjCMigrateASTConsumer : public ASTConsumer {
+  void migrateDecl(Decl *D);
+
+public:
+  std::string MigrateDir;
+  bool MigrateLiterals;
+  bool MigrateSubscripting;
+  llvm::OwningPtr<NSAPI> NSAPIObj;
+  llvm::OwningPtr<edit::EditedSource> Editor;
+  FileRemapper &Remapper;
+  FileManager &FileMgr;
+  const PreprocessingRecord *PPRec;
+  bool IsOutputFile;
+
+  ObjCMigrateASTConsumer(StringRef migrateDir,
+                         bool migrateLiterals,
+                         bool migrateSubscripting,
+                         FileRemapper &remapper,
+                         FileManager &fileMgr,
+                         const PreprocessingRecord *PPRec,
+                         bool isOutputFile = false)
+  : MigrateDir(migrateDir),
+    MigrateLiterals(migrateLiterals),
+    MigrateSubscripting(migrateSubscripting),
+    Remapper(remapper), FileMgr(fileMgr), PPRec(PPRec),
+    IsOutputFile(isOutputFile) { }
+
+protected:
+  virtual void Initialize(ASTContext &Context) {
+    NSAPIObj.reset(new NSAPI(Context));
+    Editor.reset(new edit::EditedSource(Context.getSourceManager(),
+                                        Context.getLangOptions(),
+                                        PPRec));
+  }
+
+  virtual bool HandleTopLevelDecl(DeclGroupRef DG) {
+    for (DeclGroupRef::iterator I = DG.begin(), E = DG.end(); I != E; ++I)
+      migrateDecl(*I);
+    return true;
+  }
+  virtual void HandleInterestingDecl(DeclGroupRef DG) {
+    // Ignore decls from the PCH.
+  }
+  virtual void HandleTopLevelDeclInObjCContainer(DeclGroupRef DG) {
+    ObjCMigrateASTConsumer::HandleTopLevelDecl(DG);
+  }
+
+  virtual void HandleTranslationUnit(ASTContext &Ctx);
+};
+
+}
+
+ObjCMigrateAction::ObjCMigrateAction(FrontendAction *WrappedAction,
+                             StringRef migrateDir,
+                             bool migrateLiterals,
+                             bool migrateSubscripting)
+  : WrapperFrontendAction(WrappedAction), MigrateDir(migrateDir),
+    MigrateLiterals(migrateLiterals), MigrateSubscripting(migrateSubscripting),
+    CompInst(0) {
+  if (MigrateDir.empty())
+    MigrateDir = "."; // user current directory if none is given.
+}
+
+ASTConsumer *ObjCMigrateAction::CreateASTConsumer(CompilerInstance &CI,
+                                                  StringRef InFile) {
+  ASTConsumer *
+    WrappedConsumer = WrapperFrontendAction::CreateASTConsumer(CI, InFile);
+  ASTConsumer *MTConsumer = new ObjCMigrateASTConsumer(MigrateDir,
+                                                       MigrateLiterals,
+                                                       MigrateSubscripting,
+                                                       Remapper,
+                                                    CompInst->getFileManager(),
+                          CompInst->getPreprocessor().getPreprocessingRecord()); 
+  ASTConsumer *Consumers[] = { MTConsumer, WrappedConsumer };
+  return new MultiplexConsumer(Consumers);
+}
+
+bool ObjCMigrateAction::BeginInvocation(CompilerInstance &CI) {
+  Remapper.initFromDisk(MigrateDir, CI.getDiagnostics(),
+                        /*ignoreIfFilesChanges=*/true);
+  CompInst = &CI;
+  CI.getDiagnostics().setIgnoreAllWarnings(true);
+  CI.getPreprocessorOpts().DetailedRecord = true;
+  CI.getPreprocessorOpts().DetailedRecordConditionalDirectives = true;
+  return true;
+}
+
+namespace {
+class ObjCMigrator : public RecursiveASTVisitor<ObjCMigrator> {
+  ObjCMigrateASTConsumer &Consumer;
+
+public:
+  ObjCMigrator(ObjCMigrateASTConsumer &consumer) : Consumer(consumer) { }
+
+  bool shouldVisitTemplateInstantiations() const { return false; }
+  bool shouldWalkTypesOfTypeLocs() const { return false; }
+
+  bool VisitObjCMessageExpr(ObjCMessageExpr *E) {
+    if (Consumer.MigrateLiterals) {
+      edit::Commit commit(*Consumer.Editor);
+      edit::rewriteToObjCLiteralSyntax(E, *Consumer.NSAPIObj, commit);
+      Consumer.Editor->commit(commit);
+    }
+
+    if (Consumer.MigrateSubscripting) {
+      edit::Commit commit(*Consumer.Editor);
+      edit::rewriteToObjCSubscriptSyntax(E, *Consumer.NSAPIObj, commit);
+      Consumer.Editor->commit(commit);
+    }
+
+    return true;
+  }
+
+  bool TraverseObjCMessageExpr(ObjCMessageExpr *E) {
+    // Do depth first; we want to rewrite the subexpressions first so that if
+    // we have to move expressions we will move them already rewritten.
+    for (Stmt::child_range range = E->children(); range; ++range)
+      if (!TraverseStmt(*range))
+        return false;
+
+    return WalkUpFromObjCMessageExpr(E);
+  }
+};
+}
+
+void ObjCMigrateASTConsumer::migrateDecl(Decl *D) {
+  if (!D)
+    return;
+  if (isa<ObjCMethodDecl>(D))
+    return; // Wait for the ObjC container declaration.
+
+  ObjCMigrator(*this).TraverseDecl(D);
+}
+
+namespace {
+
+class RewritesReceiver : public edit::EditsReceiver {
+  Rewriter &Rewrite;
+
+public:
+  RewritesReceiver(Rewriter &Rewrite) : Rewrite(Rewrite) { }
+
+  virtual void insert(SourceLocation loc, StringRef text) {
+    Rewrite.InsertText(loc, text);
+  }
+  virtual void replace(CharSourceRange range, StringRef text) {
+    Rewrite.ReplaceText(range.getBegin(), Rewrite.getRangeSize(range), text);
+  }
+};
+
+}
+
+void ObjCMigrateASTConsumer::HandleTranslationUnit(ASTContext &Ctx) {
+  Rewriter rewriter(Ctx.getSourceManager(), Ctx.getLangOptions());
+  RewritesReceiver Rec(rewriter);
+  Editor->applyRewrites(Rec);
+
+  for (Rewriter::buffer_iterator
+        I = rewriter.buffer_begin(), E = rewriter.buffer_end(); I != E; ++I) {
+    FileID FID = I->first;
+    RewriteBuffer &buf = I->second;
+    const FileEntry *file = Ctx.getSourceManager().getFileEntryForID(FID);
+    assert(file);
+    llvm::SmallString<512> newText;
+    llvm::raw_svector_ostream vecOS(newText);
+    buf.write(vecOS);
+    vecOS.flush();
+    llvm::MemoryBuffer *memBuf = llvm::MemoryBuffer::getMemBufferCopy(
+                   StringRef(newText.data(), newText.size()), file->getName());
+    llvm::SmallString<64> filePath(file->getName());
+    FileMgr.FixupRelativePath(filePath);
+    Remapper.remap(filePath.str(), memBuf);
+  }
+
+  if (IsOutputFile) {
+    Remapper.flushToFile(MigrateDir, Ctx.getDiagnostics());
+  } else {
+    Remapper.flushToDisk(MigrateDir, Ctx.getDiagnostics());
+  }
+}
+
+bool MigrateSourceAction::BeginInvocation(CompilerInstance &CI) {
+  CI.getPreprocessorOpts().DetailedRecord = true;
+  CI.getPreprocessorOpts().DetailedRecordConditionalDirectives = true;
+  return true;
+}
+
+ASTConsumer *MigrateSourceAction::CreateASTConsumer(CompilerInstance &CI,
+                                                  StringRef InFile) {
+  return new ObjCMigrateASTConsumer(CI.getFrontendOpts().OutputFile,
+                                    /*MigrateLiterals=*/true,
+                                    /*MigrateSubscripting=*/true,
+                                    Remapper,
+                                    CI.getFileManager(),
+                                  CI.getPreprocessor().getPreprocessingRecord(),
+                                    /*isOutputFile=*/true); 
+}