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, 329 insertions, 0 deletions

diff --git a/lib/Edit/EditedSource.cpp b/lib/Edit/EditedSource.cpp
new file mode 100644
index 0000000000..5b7fa4ad1b
--- /dev/null
+++ b/lib/Edit/EditedSource.cpp
@@ -0,0 +1,329 @@
+//===----- EditedSource.cpp - Collection of source edits ------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Edit/EditedSource.h"
+#include "clang/Edit/Commit.h"
+#include "clang/Edit/EditsReceiver.h"
+#include "clang/Lex/Lexer.h"
+#include "clang/Basic/SourceManager.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/ADT/Twine.h"
+
+using namespace clang;
+using namespace edit;
+
+void EditsReceiver::remove(CharSourceRange range) {
+  replace(range, StringRef());
+}
+
+StringRef EditedSource::copyString(const Twine &twine) {
+  llvm::SmallString<128> Data;
+  return copyString(twine.toStringRef(Data));
+}
+
+bool EditedSource::canInsertInOffset(SourceLocation OrigLoc, FileOffset Offs) {
+  FileEditsTy::iterator FA = getActionForOffset(Offs);
+  if (FA != FileEdits.end()) {
+    if (FA->first != Offs)
+      return false; // position has been removed.
+  }
+
+  if (SourceMgr.isMacroArgExpansion(OrigLoc)) {
+    SourceLocation
+      DefArgLoc = SourceMgr.getImmediateExpansionRange(OrigLoc).first;
+    SourceLocation
+      ExpLoc = SourceMgr.getImmediateExpansionRange(DefArgLoc).first;
+    llvm::DenseMap<unsigned, SourceLocation>::iterator
+      I = ExpansionToArgMap.find(ExpLoc.getRawEncoding());
+    if (I != ExpansionToArgMap.end() && I->second != DefArgLoc)
+      return false; // Trying to write in a macro argument input that has
+                 // already been written for another argument of the same macro. 
+  }
+
+  return true;
+}
+
+bool EditedSource::commitInsert(SourceLocation OrigLoc,
+                                FileOffset Offs, StringRef text,
+                                bool beforePreviousInsertions) {
+  if (!canInsertInOffset(OrigLoc, Offs))
+    return false;
+  if (text.empty())
+    return true;
+
+  if (SourceMgr.isMacroArgExpansion(OrigLoc)) {
+    SourceLocation
+      DefArgLoc = SourceMgr.getImmediateExpansionRange(OrigLoc).first;
+    SourceLocation
+      ExpLoc = SourceMgr.getImmediateExpansionRange(DefArgLoc).first;
+    ExpansionToArgMap[ExpLoc.getRawEncoding()] = DefArgLoc;
+  }
+  
+  FileEdit &FA = FileEdits[Offs];
+  if (FA.Text.empty()) {
+    FA.Text = copyString(text);
+    return true;
+  }
+
+  Twine concat;
+  if (beforePreviousInsertions)
+    concat = Twine(text) + FA.Text;
+  else
+    concat = Twine(FA.Text) +  text;
+
+  FA.Text = copyString(concat);
+  return true;
+}
+
+bool EditedSource::commitInsertFromRange(SourceLocation OrigLoc,
+                                   FileOffset Offs,
+                                   FileOffset InsertFromRangeOffs, unsigned Len,
+                                   bool beforePreviousInsertions) {
+  if (Len == 0)
+    return true;
+
+  llvm::SmallString<128> StrVec;
+  FileOffset BeginOffs = InsertFromRangeOffs;
+  FileOffset EndOffs = BeginOffs.getWithOffset(Len);
+  FileEditsTy::iterator I = FileEdits.upper_bound(BeginOffs);
+  if (I != FileEdits.begin())
+    --I;
+
+  for (; I != FileEdits.end(); ++I) {
+    FileEdit &FA = I->second;
+    FileOffset B = I->first;
+    FileOffset E = B.getWithOffset(FA.RemoveLen);
+
+    if (BeginOffs < E) {
+      if (BeginOffs >= B) {
+        BeginOffs = E;
+        ++I;
+      }
+      break;
+    }
+  }
+
+  for (; I != FileEdits.end() && EndOffs > I->first; ++I) {
+    FileEdit &FA = I->second;
+    FileOffset B = I->first;
+    FileOffset E = B.getWithOffset(FA.RemoveLen);
+
+    if (BeginOffs < B) {
+      bool Invalid = false;
+      StringRef text = getSourceText(BeginOffs, B, Invalid);
+      if (Invalid)
+        return false;
+      StrVec += text;
+    }
+    StrVec += FA.Text;
+    BeginOffs = E;
+  }
+
+  if (BeginOffs < EndOffs) {
+    bool Invalid = false;
+    StringRef text = getSourceText(BeginOffs, EndOffs, Invalid);
+    if (Invalid)
+      return false;
+    StrVec += text;
+  }
+
+  return commitInsert(OrigLoc, Offs, StrVec.str(), beforePreviousInsertions);
+}
+
+void EditedSource::commitRemove(SourceLocation OrigLoc,
+                                FileOffset BeginOffs, unsigned Len) {
+  if (Len == 0)
+    return;
+
+  FileOffset EndOffs = BeginOffs.getWithOffset(Len);
+  FileEditsTy::iterator I = FileEdits.upper_bound(BeginOffs);
+  if (I != FileEdits.begin())
+    --I;
+
+  for (; I != FileEdits.end(); ++I) {
+    FileEdit &FA = I->second;
+    FileOffset B = I->first;
+    FileOffset E = B.getWithOffset(FA.RemoveLen);
+
+    if (BeginOffs < E)
+      break;
+  }
+
+  FileOffset TopBegin, TopEnd;
+  FileEdit *TopFA = 0;
+
+  if (I == FileEdits.end()) {
+    FileEditsTy::iterator
+      NewI = FileEdits.insert(I, std::make_pair(BeginOffs, FileEdit()));
+    NewI->second.RemoveLen = Len;
+    return;
+  }
+
+  FileEdit &FA = I->second;
+  FileOffset B = I->first;
+  FileOffset E = B.getWithOffset(FA.RemoveLen);
+  if (BeginOffs < B) {
+    FileEditsTy::iterator
+      NewI = FileEdits.insert(I, std::make_pair(BeginOffs, FileEdit()));
+    TopBegin = BeginOffs;
+    TopEnd = EndOffs;
+    TopFA = &NewI->second;
+    TopFA->RemoveLen = Len;
+  } else {
+    TopBegin = B;
+    TopEnd = E;
+    TopFA = &I->second;
+    if (TopEnd >= EndOffs)
+      return;
+    unsigned diff = EndOffs.getOffset() - TopEnd.getOffset();
+    TopEnd = EndOffs;
+    TopFA->RemoveLen += diff;
+    ++I;
+  }
+
+  while (I != FileEdits.end()) {
+    FileEdit &FA = I->second;
+    FileOffset B = I->first;
+    FileOffset E = B.getWithOffset(FA.RemoveLen);
+
+    if (B >= TopEnd)
+      break;
+
+    if (E <= TopEnd) {
+      FileEdits.erase(I++);
+      continue;
+    }
+
+    if (B < TopEnd) {
+      unsigned diff = E.getOffset() - TopEnd.getOffset();
+      TopEnd = E;
+      TopFA->RemoveLen += diff;
+      FileEdits.erase(I);
+    }
+
+    break;
+  }
+}
+
+bool EditedSource::commit(const Commit &commit) {
+  if (!commit.isCommitable())
+    return false;
+
+  for (edit::Commit::edit_iterator
+         I = commit.edit_begin(), E = commit.edit_end(); I != E; ++I) {
+    const edit::Commit::Edit &edit = *I;
+    switch (edit.Kind) {
+    case edit::Commit::Act_Insert:
+      commitInsert(edit.OrigLoc, edit.Offset, edit.Text, edit.BeforePrev);
+      break;
+    case edit::Commit::Act_InsertFromRange:
+      commitInsertFromRange(edit.OrigLoc, edit.Offset,
+                            edit.InsertFromRangeOffs, edit.Length,
+                            edit.BeforePrev);
+      break;
+    case edit::Commit::Act_Remove:
+      commitRemove(edit.OrigLoc, edit.Offset, edit.Length);
+      break;
+    }
+  }
+
+  return true;
+}
+
+static void applyRewrite(EditsReceiver &receiver,
+                         StringRef text, FileOffset offs, unsigned len,
+                         const SourceManager &SM) {
+  assert(!offs.getFID().isInvalid());
+  SourceLocation Loc = SM.getLocForStartOfFile(offs.getFID());
+  Loc = Loc.getLocWithOffset(offs.getOffset());
+  assert(Loc.isFileID());
+  CharSourceRange range = CharSourceRange::getCharRange(Loc,
+                                                     Loc.getLocWithOffset(len));
+
+  if (text.empty()) {
+    assert(len);
+    receiver.remove(range);
+    return;
+  }
+
+  if (len)
+    receiver.replace(range, text);
+  else
+    receiver.insert(Loc, text);
+}
+
+void EditedSource::applyRewrites(EditsReceiver &receiver) {
+  llvm::SmallString<128> StrVec;
+  FileOffset CurOffs, CurEnd;
+  unsigned CurLen;
+
+  if (FileEdits.empty())
+    return;
+
+  FileEditsTy::iterator I = FileEdits.begin();
+  CurOffs = I->first;
+  StrVec = I->second.Text;
+  CurLen = I->second.RemoveLen;
+  CurEnd = CurOffs.getWithOffset(CurLen);
+  ++I;
+
+  for (FileEditsTy::iterator E = FileEdits.end(); I != E; ++I) {
+    FileOffset offs = I->first;
+    FileEdit act = I->second;
+    assert(offs >= CurEnd);
+
+    if (offs == CurEnd) {
+      StrVec += act.Text;
+      CurLen += act.RemoveLen;
+      CurEnd.getWithOffset(act.RemoveLen);
+      continue;
+    }
+
+    applyRewrite(receiver, StrVec.str(), CurOffs, CurLen, SourceMgr);
+    CurOffs = offs;
+    StrVec = act.Text;
+    CurLen = act.RemoveLen;
+    CurEnd = CurOffs.getWithOffset(CurLen);
+  }
+
+  applyRewrite(receiver, StrVec.str(), CurOffs, CurLen, SourceMgr);
+}
+
+void EditedSource::clearRewrites() {
+  FileEdits.clear();
+  StrAlloc.Reset();
+}
+
+StringRef EditedSource::getSourceText(FileOffset BeginOffs, FileOffset EndOffs,
+                                      bool &Invalid) {
+  assert(BeginOffs.getFID() == EndOffs.getFID());
+  assert(BeginOffs <= EndOffs);
+  SourceLocation BLoc = SourceMgr.getLocForStartOfFile(BeginOffs.getFID());
+  BLoc = BLoc.getLocWithOffset(BeginOffs.getOffset());
+  assert(BLoc.isFileID());
+  SourceLocation
+    ELoc = BLoc.getLocWithOffset(EndOffs.getOffset() - BeginOffs.getOffset());
+  return Lexer::getSourceText(CharSourceRange::getCharRange(BLoc, ELoc),
+                              SourceMgr, LangOpts, &Invalid);
+}
+
+EditedSource::FileEditsTy::iterator
+EditedSource::getActionForOffset(FileOffset Offs) {
+  FileEditsTy::iterator I = FileEdits.upper_bound(Offs);
+  if (I == FileEdits.begin())
+    return FileEdits.end();
+  --I;
+  FileEdit &FA = I->second;
+  FileOffset B = I->first;
+  FileOffset E = B.getWithOffset(FA.RemoveLen);
+  if (Offs >= B && Offs < E)
+    return I;
+
+  return FileEdits.end();
+}