Imported Upstream version 6.10.0.49

Former-commit-id: 1d6753294b2993e1fbf92de9366bb9544db4189b

external/llvm-project/clang/lib/Rewrite/CMakeLists.txt

@@ -0,0 +1,15 @@
+set(LLVM_LINK_COMPONENTS
+  Support
+  )
+
+add_clang_library(clangRewrite
+  DeltaTree.cpp
+  HTMLRewrite.cpp
+  RewriteRope.cpp
+  Rewriter.cpp
+  TokenRewriter.cpp
+
+  LINK_LIBS
+  clangBasic
+  clangLex
+  )

external/llvm-project/clang/lib/Rewrite/DeltaTree.cpp

@@ -0,0 +1,464 @@
+//===--- DeltaTree.cpp - B-Tree for Rewrite Delta tracking ----------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the DeltaTree and related classes.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Rewrite/Core/DeltaTree.h"
+#include "clang/Basic/LLVM.h"
+#include <cstdio>
+#include <cstring>
+using namespace clang;
+
+/// The DeltaTree class is a multiway search tree (BTree) structure with some
+/// fancy features.  B-Trees are generally more memory and cache efficient
+/// than binary trees, because they store multiple keys/values in each node.
+///
+/// DeltaTree implements a key/value mapping from FileIndex to Delta, allowing
+/// fast lookup by FileIndex.  However, an added (important) bonus is that it
+/// can also efficiently tell us the full accumulated delta for a specific
+/// file offset as well, without traversing the whole tree.
+///
+/// The nodes of the tree are made up of instances of two classes:
+/// DeltaTreeNode and DeltaTreeInteriorNode.  The later subclasses the
+/// former and adds children pointers.  Each node knows the full delta of all
+/// entries (recursively) contained inside of it, which allows us to get the
+/// full delta implied by a whole subtree in constant time.
+
+namespace {
+  /// SourceDelta - As code in the original input buffer is added and deleted,
+  /// SourceDelta records are used to keep track of how the input SourceLocation
+  /// object is mapped into the output buffer.
+  struct SourceDelta {
+    unsigned FileLoc;
+    int Delta;
+
+    static SourceDelta get(unsigned Loc, int D) {
+      SourceDelta Delta;
+      Delta.FileLoc = Loc;
+      Delta.Delta = D;
+      return Delta;
+    }
+  };
+  
+  /// DeltaTreeNode - The common part of all nodes.
+  ///
+  class DeltaTreeNode {
+  public:
+    struct InsertResult {
+      DeltaTreeNode *LHS, *RHS;
+      SourceDelta Split;
+    };
+    
+  private:
+    friend class DeltaTreeInteriorNode;
+
+    /// WidthFactor - This controls the number of K/V slots held in the BTree:
+    /// how wide it is.  Each level of the BTree is guaranteed to have at least
+    /// WidthFactor-1 K/V pairs (except the root) and may have at most
+    /// 2*WidthFactor-1 K/V pairs.
+    enum { WidthFactor = 8 };
+
+    /// Values - This tracks the SourceDelta's currently in this node.
+    ///
+    SourceDelta Values[2*WidthFactor-1];
+
+    /// NumValuesUsed - This tracks the number of values this node currently
+    /// holds.
+    unsigned char NumValuesUsed;
+
+    /// IsLeaf - This is true if this is a leaf of the btree.  If false, this is
+    /// an interior node, and is actually an instance of DeltaTreeInteriorNode.
+    bool IsLeaf;
+
+    /// FullDelta - This is the full delta of all the values in this node and
+    /// all children nodes.
+    int FullDelta;
+  public:
+    DeltaTreeNode(bool isLeaf = true)
+      : NumValuesUsed(0), IsLeaf(isLeaf), FullDelta(0) {}
+
+    bool isLeaf() const { return IsLeaf; }
+    int getFullDelta() const { return FullDelta; }
+    bool isFull() const { return NumValuesUsed == 2*WidthFactor-1; }
+
+    unsigned getNumValuesUsed() const { return NumValuesUsed; }
+    const SourceDelta &getValue(unsigned i) const {
+      assert(i < NumValuesUsed && "Invalid value #");
+      return Values[i];
+    }
+    SourceDelta &getValue(unsigned i) {
+      assert(i < NumValuesUsed && "Invalid value #");
+      return Values[i];
+    }
+
+    /// DoInsertion - Do an insertion of the specified FileIndex/Delta pair into
+    /// this node.  If insertion is easy, do it and return false.  Otherwise,
+    /// split the node, populate InsertRes with info about the split, and return
+    /// true.
+    bool DoInsertion(unsigned FileIndex, int Delta, InsertResult *InsertRes);
+
+    void DoSplit(InsertResult &InsertRes);
+
+
+    /// RecomputeFullDeltaLocally - Recompute the FullDelta field by doing a
+    /// local walk over our contained deltas.
+    void RecomputeFullDeltaLocally();
+
+    void Destroy();
+  };
+} // end anonymous namespace
+
+namespace {
+  /// DeltaTreeInteriorNode - When isLeaf = false, a node has child pointers.
+  /// This class tracks them.
+  class DeltaTreeInteriorNode : public DeltaTreeNode {
+    DeltaTreeNode *Children[2*WidthFactor];
+    ~DeltaTreeInteriorNode() {
+      for (unsigned i = 0, e = NumValuesUsed+1; i != e; ++i)
+        Children[i]->Destroy();
+    }
+    friend class DeltaTreeNode;
+  public:
+    DeltaTreeInteriorNode() : DeltaTreeNode(false /*nonleaf*/) {}
+
+    DeltaTreeInteriorNode(const InsertResult &IR)
+      : DeltaTreeNode(false /*nonleaf*/) {
+      Children[0] = IR.LHS;
+      Children[1] = IR.RHS;
+      Values[0] = IR.Split;
+      FullDelta = IR.LHS->getFullDelta()+IR.RHS->getFullDelta()+IR.Split.Delta;
+      NumValuesUsed = 1;
+    }
+
+    const DeltaTreeNode *getChild(unsigned i) const {
+      assert(i < getNumValuesUsed()+1 && "Invalid child");
+      return Children[i];
+    }
+    DeltaTreeNode *getChild(unsigned i) {
+      assert(i < getNumValuesUsed()+1 && "Invalid child");
+      return Children[i];
+    }
+
+    static inline bool classof(const DeltaTreeNode *N) { return !N->isLeaf(); }
+  };
+}
+
+
+/// Destroy - A 'virtual' destructor.
+void DeltaTreeNode::Destroy() {
+  if (isLeaf())
+    delete this;
+  else
+    delete cast<DeltaTreeInteriorNode>(this);
+}
+
+/// RecomputeFullDeltaLocally - Recompute the FullDelta field by doing a
+/// local walk over our contained deltas.
+void DeltaTreeNode::RecomputeFullDeltaLocally() {
+  int NewFullDelta = 0;
+  for (unsigned i = 0, e = getNumValuesUsed(); i != e; ++i)
+    NewFullDelta += Values[i].Delta;
+  if (DeltaTreeInteriorNode *IN = dyn_cast<DeltaTreeInteriorNode>(this))
+    for (unsigned i = 0, e = getNumValuesUsed()+1; i != e; ++i)
+      NewFullDelta += IN->getChild(i)->getFullDelta();
+  FullDelta = NewFullDelta;
+}
+
+/// DoInsertion - Do an insertion of the specified FileIndex/Delta pair into
+/// this node.  If insertion is easy, do it and return false.  Otherwise,
+/// split the node, populate InsertRes with info about the split, and return
+/// true.
+bool DeltaTreeNode::DoInsertion(unsigned FileIndex, int Delta,
+                                InsertResult *InsertRes) {
+  // Maintain full delta for this node.
+  FullDelta += Delta;
+
+  // Find the insertion point, the first delta whose index is >= FileIndex.
+  unsigned i = 0, e = getNumValuesUsed();
+  while (i != e && FileIndex > getValue(i).FileLoc)
+    ++i;
+
+  // If we found an a record for exactly this file index, just merge this
+  // value into the pre-existing record and finish early.
+  if (i != e && getValue(i).FileLoc == FileIndex) {
+    // NOTE: Delta could drop to zero here.  This means that the delta entry is
+    // useless and could be removed.  Supporting erases is more complex than
+    // leaving an entry with Delta=0, so we just leave an entry with Delta=0 in
+    // the tree.
+    Values[i].Delta += Delta;
+    return false;
+  }
+
+  // Otherwise, we found an insertion point, and we know that the value at the
+  // specified index is > FileIndex.  Handle the leaf case first.
+  if (isLeaf()) {
+    if (!isFull()) {
+      // For an insertion into a non-full leaf node, just insert the value in
+      // its sorted position.  This requires moving later values over.
+      if (i != e)
+        memmove(&Values[i+1], &Values[i], sizeof(Values[0])*(e-i));
+      Values[i] = SourceDelta::get(FileIndex, Delta);
+      ++NumValuesUsed;
+      return false;
+    }
+
+    // Otherwise, if this is leaf is full, split the node at its median, insert
+    // the value into one of the children, and return the result.
+    assert(InsertRes && "No result location specified");
+    DoSplit(*InsertRes);
+
+    if (InsertRes->Split.FileLoc > FileIndex)
+      InsertRes->LHS->DoInsertion(FileIndex, Delta, nullptr /*can't fail*/);
+    else
+      InsertRes->RHS->DoInsertion(FileIndex, Delta, nullptr /*can't fail*/);
+    return true;
+  }
+
+  // Otherwise, this is an interior node.  Send the request down the tree.
+  DeltaTreeInteriorNode *IN = cast<DeltaTreeInteriorNode>(this);
+  if (!IN->Children[i]->DoInsertion(FileIndex, Delta, InsertRes))
+    return false; // If there was space in the child, just return.
+
+  // Okay, this split the subtree, producing a new value and two children to
+  // insert here.  If this node is non-full, we can just insert it directly.
+  if (!isFull()) {
+    // Now that we have two nodes and a new element, insert the perclated value
+    // into ourself by moving all the later values/children down, then inserting
+    // the new one.
+    if (i != e)
+      memmove(&IN->Children[i+2], &IN->Children[i+1],
+              (e-i)*sizeof(IN->Children[0]));
+    IN->Children[i] = InsertRes->LHS;
+    IN->Children[i+1] = InsertRes->RHS;
+
+    if (e != i)
+      memmove(&Values[i+1], &Values[i], (e-i)*sizeof(Values[0]));
+    Values[i] = InsertRes->Split;
+    ++NumValuesUsed;
+    return false;
+  }
+
+  // Finally, if this interior node was full and a node is percolated up, split
+  // ourself and return that up the chain.  Start by saving all our info to
+  // avoid having the split clobber it.
+  IN->Children[i] = InsertRes->LHS;
+  DeltaTreeNode *SubRHS = InsertRes->RHS;
+  SourceDelta SubSplit = InsertRes->Split;
+
+  // Do the split.
+  DoSplit(*InsertRes);
+
+  // Figure out where to insert SubRHS/NewSplit.
+  DeltaTreeInteriorNode *InsertSide;
+  if (SubSplit.FileLoc < InsertRes->Split.FileLoc)
+    InsertSide = cast<DeltaTreeInteriorNode>(InsertRes->LHS);
+  else
+    InsertSide = cast<DeltaTreeInteriorNode>(InsertRes->RHS);
+
+  // We now have a non-empty interior node 'InsertSide' to insert
+  // SubRHS/SubSplit into.  Find out where to insert SubSplit.
+
+  // Find the insertion point, the first delta whose index is >SubSplit.FileLoc.
+  i = 0; e = InsertSide->getNumValuesUsed();
+  while (i != e && SubSplit.FileLoc > InsertSide->getValue(i).FileLoc)
+    ++i;
+
+  // Now we know that i is the place to insert the split value into.  Insert it
+  // and the child right after it.
+  if (i != e)
+    memmove(&InsertSide->Children[i+2], &InsertSide->Children[i+1],
+            (e-i)*sizeof(IN->Children[0]));
+  InsertSide->Children[i+1] = SubRHS;
+
+  if (e != i)
+    memmove(&InsertSide->Values[i+1], &InsertSide->Values[i],
+            (e-i)*sizeof(Values[0]));
+  InsertSide->Values[i] = SubSplit;
+  ++InsertSide->NumValuesUsed;
+  InsertSide->FullDelta += SubSplit.Delta + SubRHS->getFullDelta();
+  return true;
+}
+
+/// DoSplit - Split the currently full node (which has 2*WidthFactor-1 values)
+/// into two subtrees each with "WidthFactor-1" values and a pivot value.
+/// Return the pieces in InsertRes.
+void DeltaTreeNode::DoSplit(InsertResult &InsertRes) {
+  assert(isFull() && "Why split a non-full node?");
+
+  // Since this node is full, it contains 2*WidthFactor-1 values.  We move
+  // the first 'WidthFactor-1' values to the LHS child (which we leave in this
+  // node), propagate one value up, and move the last 'WidthFactor-1' values
+  // into the RHS child.
+
+  // Create the new child node.
+  DeltaTreeNode *NewNode;
+  if (DeltaTreeInteriorNode *IN = dyn_cast<DeltaTreeInteriorNode>(this)) {
+    // If this is an interior node, also move over 'WidthFactor' children
+    // into the new node.
+    DeltaTreeInteriorNode *New = new DeltaTreeInteriorNode();
+    memcpy(&New->Children[0], &IN->Children[WidthFactor],
+           WidthFactor*sizeof(IN->Children[0]));
+    NewNode = New;
+  } else {
+    // Just create the new leaf node.
+    NewNode = new DeltaTreeNode();
+  }
+
+  // Move over the last 'WidthFactor-1' values from here to NewNode.
+  memcpy(&NewNode->Values[0], &Values[WidthFactor],
+         (WidthFactor-1)*sizeof(Values[0]));
+
+  // Decrease the number of values in the two nodes.
+  NewNode->NumValuesUsed = NumValuesUsed = WidthFactor-1;
+
+  // Recompute the two nodes' full delta.
+  NewNode->RecomputeFullDeltaLocally();
+  RecomputeFullDeltaLocally();
+
+  InsertRes.LHS = this;
+  InsertRes.RHS = NewNode;
+  InsertRes.Split = Values[WidthFactor-1];
+}
+
+
+
+//===----------------------------------------------------------------------===//
+//                        DeltaTree Implementation
+//===----------------------------------------------------------------------===//
+
+//#define VERIFY_TREE
+
+#ifdef VERIFY_TREE
+/// VerifyTree - Walk the btree performing assertions on various properties to
+/// verify consistency.  This is useful for debugging new changes to the tree.
+static void VerifyTree(const DeltaTreeNode *N) {
+  const DeltaTreeInteriorNode *IN = dyn_cast<DeltaTreeInteriorNode>(N);
+  if (IN == 0) {
+    // Verify leaves, just ensure that FullDelta matches up and the elements
+    // are in proper order.
+    int FullDelta = 0;
+    for (unsigned i = 0, e = N->getNumValuesUsed(); i != e; ++i) {
+      if (i)
+        assert(N->getValue(i-1).FileLoc < N->getValue(i).FileLoc);
+      FullDelta += N->getValue(i).Delta;
+    }
+    assert(FullDelta == N->getFullDelta());
+    return;
+  }
+
+  // Verify interior nodes: Ensure that FullDelta matches up and the
+  // elements are in proper order and the children are in proper order.
+  int FullDelta = 0;
+  for (unsigned i = 0, e = IN->getNumValuesUsed(); i != e; ++i) {
+    const SourceDelta &IVal = N->getValue(i);
+    const DeltaTreeNode *IChild = IN->getChild(i);
+    if (i)
+      assert(IN->getValue(i-1).FileLoc < IVal.FileLoc);
+    FullDelta += IVal.Delta;
+    FullDelta += IChild->getFullDelta();
+
+    // The largest value in child #i should be smaller than FileLoc.
+    assert(IChild->getValue(IChild->getNumValuesUsed()-1).FileLoc <
+           IVal.FileLoc);
+
+    // The smallest value in child #i+1 should be larger than FileLoc.
+    assert(IN->getChild(i+1)->getValue(0).FileLoc > IVal.FileLoc);
+    VerifyTree(IChild);
+  }
+
+  FullDelta += IN->getChild(IN->getNumValuesUsed())->getFullDelta();
+
+  assert(FullDelta == N->getFullDelta());
+}
+#endif  // VERIFY_TREE
+
+static DeltaTreeNode *getRoot(void *Root) {
+  return (DeltaTreeNode*)Root;
+}
+
+DeltaTree::DeltaTree() {
+  Root = new DeltaTreeNode();
+}
+DeltaTree::DeltaTree(const DeltaTree &RHS) {
+  // Currently we only support copying when the RHS is empty.
+  assert(getRoot(RHS.Root)->getNumValuesUsed() == 0 &&
+         "Can only copy empty tree");
+  Root = new DeltaTreeNode();
+}
+
+DeltaTree::~DeltaTree() {
+  getRoot(Root)->Destroy();
+}
+
+/// getDeltaAt - Return the accumulated delta at the specified file offset.
+/// This includes all insertions or delections that occurred *before* the
+/// specified file index.
+int DeltaTree::getDeltaAt(unsigned FileIndex) const {
+  const DeltaTreeNode *Node = getRoot(Root);
+
+  int Result = 0;
+
+  // Walk down the tree.
+  while (1) {
+    // For all nodes, include any local deltas before the specified file
+    // index by summing them up directly.  Keep track of how many were
+    // included.
+    unsigned NumValsGreater = 0;
+    for (unsigned e = Node->getNumValuesUsed(); NumValsGreater != e;
+         ++NumValsGreater) {
+      const SourceDelta &Val = Node->getValue(NumValsGreater);
+
+      if (Val.FileLoc >= FileIndex)
+        break;
+      Result += Val.Delta;
+    }
+
+    // If we have an interior node, include information about children and
+    // recurse.  Otherwise, if we have a leaf, we're done.
+    const DeltaTreeInteriorNode *IN = dyn_cast<DeltaTreeInteriorNode>(Node);
+    if (!IN) return Result;
+
+    // Include any children to the left of the values we skipped, all of
+    // their deltas should be included as well.
+    for (unsigned i = 0; i != NumValsGreater; ++i)
+      Result += IN->getChild(i)->getFullDelta();
+
+    // If we found exactly the value we were looking for, break off the
+    // search early.  There is no need to search the RHS of the value for
+    // partial results.
+    if (NumValsGreater != Node->getNumValuesUsed() &&
+        Node->getValue(NumValsGreater).FileLoc == FileIndex)
+      return Result+IN->getChild(NumValsGreater)->getFullDelta();
+
+    // Otherwise, traverse down the tree.  The selected subtree may be
+    // partially included in the range.
+    Node = IN->getChild(NumValsGreater);
+  }
+  // NOT REACHED.
+}
+
+/// AddDelta - When a change is made that shifts around the text buffer,
+/// this method is used to record that info.  It inserts a delta of 'Delta'
+/// into the current DeltaTree at offset FileIndex.
+void DeltaTree::AddDelta(unsigned FileIndex, int Delta) {
+  assert(Delta && "Adding a noop?");
+  DeltaTreeNode *MyRoot = getRoot(Root);
+
+  DeltaTreeNode::InsertResult InsertRes;
+  if (MyRoot->DoInsertion(FileIndex, Delta, &InsertRes)) {
+    Root = MyRoot = new DeltaTreeInteriorNode(InsertRes);
+  }
+
+#ifdef VERIFY_TREE
+  VerifyTree(MyRoot);
+#endif
+}
+

external/llvm-project/clang/lib/Rewrite/Rewriter.cpp

@@ -0,0 +1,458 @@
+//===--- Rewriter.cpp - Code rewriting interface --------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+//  This file defines the Rewriter class, which is used for code
+//  transformations.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Rewrite/Core/Rewriter.h"
+#include "clang/Basic/Diagnostic.h"
+#include "clang/Basic/DiagnosticIDs.h"
+#include "clang/Basic/SourceManager.h"
+#include "clang/Lex/Lexer.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/Support/FileSystem.h"
+#include "llvm/Support/raw_ostream.h"
+using namespace clang;
+
+raw_ostream &RewriteBuffer::write(raw_ostream &os) const {
+  // Walk RewriteRope chunks efficiently using MoveToNextPiece() instead of the
+  // character iterator.
+  for (RopePieceBTreeIterator I = begin(), E = end(); I != E;
+       I.MoveToNextPiece())
+    os << I.piece();
+  return os;
+}
+
+/// \brief Return true if this character is non-new-line whitespace:
+/// ' ', '\\t', '\\f', '\\v', '\\r'.
+static inline bool isWhitespaceExceptNL(unsigned char c) {
+  switch (c) {
+  case ' ':
+  case '\t':
+  case '\f':
+  case '\v':
+  case '\r':
+    return true;
+  default:
+    return false;
+  }
+}
+
+void RewriteBuffer::RemoveText(unsigned OrigOffset, unsigned Size,
+                               bool removeLineIfEmpty) {
+  // Nothing to remove, exit early.
+  if (Size == 0) return;
+
+  unsigned RealOffset = getMappedOffset(OrigOffset, true);
+  assert(RealOffset+Size <= Buffer.size() && "Invalid location");
+
+  // Remove the dead characters.
+  Buffer.erase(RealOffset, Size);
+
+  // Add a delta so that future changes are offset correctly.
+  AddReplaceDelta(OrigOffset, -Size);
+
+  if (removeLineIfEmpty) {
+    // Find the line that the remove occurred and if it is completely empty
+    // remove the line as well.
+
+    iterator curLineStart = begin();
+    unsigned curLineStartOffs = 0;
+    iterator posI = begin();
+    for (unsigned i = 0; i != RealOffset; ++i) {
+      if (*posI == '\n') {
+        curLineStart = posI;
+        ++curLineStart;
+        curLineStartOffs = i + 1;
+      }
+      ++posI;
+    }
+  
+    unsigned lineSize = 0;
+    posI = curLineStart;
+    while (posI != end() && isWhitespaceExceptNL(*posI)) {
+      ++posI;
+      ++lineSize;
+    }
+    if (posI != end() && *posI == '\n') {
+      Buffer.erase(curLineStartOffs, lineSize + 1/* + '\n'*/);
+      AddReplaceDelta(curLineStartOffs, -(lineSize + 1/* + '\n'*/));
+    }
+  }
+}
+
+void RewriteBuffer::InsertText(unsigned OrigOffset, StringRef Str,
+                               bool InsertAfter) {
+
+  // Nothing to insert, exit early.
+  if (Str.empty()) return;
+
+  unsigned RealOffset = getMappedOffset(OrigOffset, InsertAfter);
+  Buffer.insert(RealOffset, Str.begin(), Str.end());
+
+  // Add a delta so that future changes are offset correctly.
+  AddInsertDelta(OrigOffset, Str.size());
+}
+
+/// ReplaceText - This method replaces a range of characters in the input
+/// buffer with a new string.  This is effectively a combined "remove+insert"
+/// operation.
+void RewriteBuffer::ReplaceText(unsigned OrigOffset, unsigned OrigLength,
+                                StringRef NewStr) {
+  unsigned RealOffset = getMappedOffset(OrigOffset, true);
+  Buffer.erase(RealOffset, OrigLength);
+  Buffer.insert(RealOffset, NewStr.begin(), NewStr.end());
+  if (OrigLength != NewStr.size())
+    AddReplaceDelta(OrigOffset, NewStr.size() - OrigLength);
+}
+
+
+//===----------------------------------------------------------------------===//
+// Rewriter class
+//===----------------------------------------------------------------------===//
+
+/// getRangeSize - Return the size in bytes of the specified range if they
+/// are in the same file.  If not, this returns -1.
+int Rewriter::getRangeSize(const CharSourceRange &Range,
+                           RewriteOptions opts) const {
+  if (!isRewritable(Range.getBegin()) ||
+      !isRewritable(Range.getEnd())) return -1;
+
+  FileID StartFileID, EndFileID;
+  unsigned StartOff, EndOff;
+
+  StartOff = getLocationOffsetAndFileID(Range.getBegin(), StartFileID);
+  EndOff   = getLocationOffsetAndFileID(Range.getEnd(), EndFileID);
+
+  if (StartFileID != EndFileID)
+    return -1;
+
+  // If edits have been made to this buffer, the delta between the range may
+  // have changed.
+  std::map<FileID, RewriteBuffer>::const_iterator I =
+    RewriteBuffers.find(StartFileID);
+  if (I != RewriteBuffers.end()) {
+    const RewriteBuffer &RB = I->second;
+    EndOff = RB.getMappedOffset(EndOff, opts.IncludeInsertsAtEndOfRange);
+    StartOff = RB.getMappedOffset(StartOff, !opts.IncludeInsertsAtBeginOfRange);
+  }
+
+
+  // Adjust the end offset to the end of the last token, instead of being the
+  // start of the last token if this is a token range.
+  if (Range.isTokenRange())
+    EndOff += Lexer::MeasureTokenLength(Range.getEnd(), *SourceMgr, *LangOpts);
+
+  return EndOff-StartOff;
+}
+
+int Rewriter::getRangeSize(SourceRange Range, RewriteOptions opts) const {
+  return getRangeSize(CharSourceRange::getTokenRange(Range), opts);
+}
+
+
+/// getRewrittenText - Return the rewritten form of the text in the specified
+/// range.  If the start or end of the range was unrewritable or if they are
+/// in different buffers, this returns an empty string.
+///
+/// Note that this method is not particularly efficient.
+///
+std::string Rewriter::getRewrittenText(SourceRange Range) const {
+  if (!isRewritable(Range.getBegin()) ||
+      !isRewritable(Range.getEnd()))
+    return "";
+
+  FileID StartFileID, EndFileID;
+  unsigned StartOff, EndOff;
+  StartOff = getLocationOffsetAndFileID(Range.getBegin(), StartFileID);
+  EndOff   = getLocationOffsetAndFileID(Range.getEnd(), EndFileID);
+
+  if (StartFileID != EndFileID)
+    return ""; // Start and end in different buffers.
+
+  // If edits have been made to this buffer, the delta between the range may
+  // have changed.
+  std::map<FileID, RewriteBuffer>::const_iterator I =
+    RewriteBuffers.find(StartFileID);
+  if (I == RewriteBuffers.end()) {
+    // If the buffer hasn't been rewritten, just return the text from the input.
+    const char *Ptr = SourceMgr->getCharacterData(Range.getBegin());
+
+    // Adjust the end offset to the end of the last token, instead of being the
+    // start of the last token.
+    EndOff += Lexer::MeasureTokenLength(Range.getEnd(), *SourceMgr, *LangOpts);
+    return std::string(Ptr, Ptr+EndOff-StartOff);
+  }
+
+  const RewriteBuffer &RB = I->second;
+  EndOff = RB.getMappedOffset(EndOff, true);
+  StartOff = RB.getMappedOffset(StartOff);
+
+  // Adjust the end offset to the end of the last token, instead of being the
+  // start of the last token.
+  EndOff += Lexer::MeasureTokenLength(Range.getEnd(), *SourceMgr, *LangOpts);
+
+  // Advance the iterators to the right spot, yay for linear time algorithms.
+  RewriteBuffer::iterator Start = RB.begin();
+  std::advance(Start, StartOff);
+  RewriteBuffer::iterator End = Start;
+  std::advance(End, EndOff-StartOff);
+
+  return std::string(Start, End);
+}
+
+unsigned Rewriter::getLocationOffsetAndFileID(SourceLocation Loc,
+                                              FileID &FID) const {
+  assert(Loc.isValid() && "Invalid location");
+  std::pair<FileID,unsigned> V = SourceMgr->getDecomposedLoc(Loc);
+  FID = V.first;
+  return V.second;
+}
+
+
+/// getEditBuffer - Get or create a RewriteBuffer for the specified FileID.
+///
+RewriteBuffer &Rewriter::getEditBuffer(FileID FID) {
+  std::map<FileID, RewriteBuffer>::iterator I =
+    RewriteBuffers.lower_bound(FID);
+  if (I != RewriteBuffers.end() && I->first == FID)
+    return I->second;
+  I = RewriteBuffers.insert(I, std::make_pair(FID, RewriteBuffer()));
+
+  StringRef MB = SourceMgr->getBufferData(FID);
+  I->second.Initialize(MB.begin(), MB.end());
+
+  return I->second;
+}
+
+/// InsertText - Insert the specified string at the specified location in the
+/// original buffer.
+bool Rewriter::InsertText(SourceLocation Loc, StringRef Str,
+                          bool InsertAfter, bool indentNewLines) {
+  if (!isRewritable(Loc)) return true;
+  FileID FID;
+  unsigned StartOffs = getLocationOffsetAndFileID(Loc, FID);
+
+  SmallString<128> indentedStr;
+  if (indentNewLines && Str.find('\n') != StringRef::npos) {
+    StringRef MB = SourceMgr->getBufferData(FID);
+
+    unsigned lineNo = SourceMgr->getLineNumber(FID, StartOffs) - 1;
+    const SrcMgr::ContentCache *
+        Content = SourceMgr->getSLocEntry(FID).getFile().getContentCache();
+    unsigned lineOffs = Content->SourceLineCache[lineNo];
+
+    // Find the whitespace at the start of the line.
+    StringRef indentSpace;
+    {
+      unsigned i = lineOffs;
+      while (isWhitespaceExceptNL(MB[i]))
+        ++i;
+      indentSpace = MB.substr(lineOffs, i-lineOffs);
+    }
+
+    SmallVector<StringRef, 4> lines;
+    Str.split(lines, "\n");
+
+    for (unsigned i = 0, e = lines.size(); i != e; ++i) {
+      indentedStr += lines[i];
+      if (i < e-1) {
+        indentedStr += '\n';
+        indentedStr += indentSpace;
+      }
+    }
+    Str = indentedStr.str();
+  }
+
+  getEditBuffer(FID).InsertText(StartOffs, Str, InsertAfter);
+  return false;
+}
+
+bool Rewriter::InsertTextAfterToken(SourceLocation Loc, StringRef Str) {
+  if (!isRewritable(Loc)) return true;
+  FileID FID;
+  unsigned StartOffs = getLocationOffsetAndFileID(Loc, FID);
+  RewriteOptions rangeOpts;
+  rangeOpts.IncludeInsertsAtBeginOfRange = false;
+  StartOffs += getRangeSize(SourceRange(Loc, Loc), rangeOpts);
+  getEditBuffer(FID).InsertText(StartOffs, Str, /*InsertAfter*/true);
+  return false;
+}
+
+/// RemoveText - Remove the specified text region.
+bool Rewriter::RemoveText(SourceLocation Start, unsigned Length,
+                          RewriteOptions opts) {
+  if (!isRewritable(Start)) return true;
+  FileID FID;
+  unsigned StartOffs = getLocationOffsetAndFileID(Start, FID);
+  getEditBuffer(FID).RemoveText(StartOffs, Length, opts.RemoveLineIfEmpty);
+  return false;
+}
+
+/// ReplaceText - This method replaces a range of characters in the input
+/// buffer with a new string.  This is effectively a combined "remove/insert"
+/// operation.
+bool Rewriter::ReplaceText(SourceLocation Start, unsigned OrigLength,
+                           StringRef NewStr) {
+  if (!isRewritable(Start)) return true;
+  FileID StartFileID;
+  unsigned StartOffs = getLocationOffsetAndFileID(Start, StartFileID);
+
+  getEditBuffer(StartFileID).ReplaceText(StartOffs, OrigLength, NewStr);
+  return false;
+}
+
+bool Rewriter::ReplaceText(SourceRange range, SourceRange replacementRange) {
+  if (!isRewritable(range.getBegin())) return true;
+  if (!isRewritable(range.getEnd())) return true;
+  if (replacementRange.isInvalid()) return true;
+  SourceLocation start = range.getBegin();
+  unsigned origLength = getRangeSize(range);
+  unsigned newLength = getRangeSize(replacementRange);
+  FileID FID;
+  unsigned newOffs = getLocationOffsetAndFileID(replacementRange.getBegin(),
+                                                FID);
+  StringRef MB = SourceMgr->getBufferData(FID);
+  return ReplaceText(start, origLength, MB.substr(newOffs, newLength));
+}
+
+bool Rewriter::IncreaseIndentation(CharSourceRange range,
+                                   SourceLocation parentIndent) {
+  if (range.isInvalid()) return true;
+  if (!isRewritable(range.getBegin())) return true;
+  if (!isRewritable(range.getEnd())) return true;
+  if (!isRewritable(parentIndent)) return true;
+
+  FileID StartFileID, EndFileID, parentFileID;
+  unsigned StartOff, EndOff, parentOff;
+
+  StartOff = getLocationOffsetAndFileID(range.getBegin(), StartFileID);
+  EndOff   = getLocationOffsetAndFileID(range.getEnd(), EndFileID);
+  parentOff = getLocationOffsetAndFileID(parentIndent, parentFileID);
+
+  if (StartFileID != EndFileID || StartFileID != parentFileID)
+    return true;
+  if (StartOff > EndOff)
+    return true;
+
+  FileID FID = StartFileID;
+  StringRef MB = SourceMgr->getBufferData(FID);
+
+  unsigned parentLineNo = SourceMgr->getLineNumber(FID, parentOff) - 1;
+  unsigned startLineNo = SourceMgr->getLineNumber(FID, StartOff) - 1;
+  unsigned endLineNo = SourceMgr->getLineNumber(FID, EndOff) - 1;
+  
+  const SrcMgr::ContentCache *
+      Content = SourceMgr->getSLocEntry(FID).getFile().getContentCache();
+  
+  // Find where the lines start.
+  unsigned parentLineOffs = Content->SourceLineCache[parentLineNo];
+  unsigned startLineOffs = Content->SourceLineCache[startLineNo];
+
+  // Find the whitespace at the start of each line.
+  StringRef parentSpace, startSpace;
+  {
+    unsigned i = parentLineOffs;
+    while (isWhitespaceExceptNL(MB[i]))
+      ++i;
+    parentSpace = MB.substr(parentLineOffs, i-parentLineOffs);
+
+    i = startLineOffs;
+    while (isWhitespaceExceptNL(MB[i]))
+      ++i;
+    startSpace = MB.substr(startLineOffs, i-startLineOffs);
+  }
+  if (parentSpace.size() >= startSpace.size())
+    return true;
+  if (!startSpace.startswith(parentSpace))
+    return true;
+
+  StringRef indent = startSpace.substr(parentSpace.size());
+
+  // Indent the lines between start/end offsets.
+  RewriteBuffer &RB = getEditBuffer(FID);
+  for (unsigned lineNo = startLineNo; lineNo <= endLineNo; ++lineNo) {
+    unsigned offs = Content->SourceLineCache[lineNo];
+    unsigned i = offs;
+    while (isWhitespaceExceptNL(MB[i]))
+      ++i;
+    StringRef origIndent = MB.substr(offs, i-offs);
+    if (origIndent.startswith(startSpace))
+      RB.InsertText(offs, indent, /*InsertAfter=*/false);
+  }
+
+  return false;
+}
+
+namespace {
+// A wrapper for a file stream that atomically overwrites the target.
+//
+// Creates a file output stream for a temporary file in the constructor,
+// which is later accessible via getStream() if ok() return true.
+// Flushes the stream and moves the temporary file to the target location
+// in the destructor.
+class AtomicallyMovedFile {
+public:
+  AtomicallyMovedFile(DiagnosticsEngine &Diagnostics, StringRef Filename,
+                      bool &AllWritten)
+    : Diagnostics(Diagnostics), Filename(Filename), AllWritten(AllWritten) {
+    TempFilename = Filename;
+    TempFilename += "-%%%%%%%%";
+    int FD;
+    if (llvm::sys::fs::createUniqueFile(TempFilename, FD, TempFilename)) {
+      AllWritten = false;
+      Diagnostics.Report(clang::diag::err_unable_to_make_temp)
+        << TempFilename;
+    } else {
+      FileStream.reset(new llvm::raw_fd_ostream(FD, /*shouldClose=*/true));
+    }
+  }
+
+  ~AtomicallyMovedFile() {
+    if (!ok()) return;
+
+    // Close (will also flush) theFileStream.
+    FileStream->close();
+    if (std::error_code ec = llvm::sys::fs::rename(TempFilename, Filename)) {
+      AllWritten = false;
+      Diagnostics.Report(clang::diag::err_unable_to_rename_temp)
+        << TempFilename << Filename << ec.message();
+      // If the remove fails, there's not a lot we can do - this is already an
+      // error.
+      llvm::sys::fs::remove(TempFilename);
+    }
+  }
+
+  bool ok() { return (bool)FileStream; }
+  raw_ostream &getStream() { return *FileStream; }
+
+private:
+  DiagnosticsEngine &Diagnostics;
+  StringRef Filename;
+  SmallString<128> TempFilename;
+  std::unique_ptr<llvm::raw_fd_ostream> FileStream;
+  bool &AllWritten;
+};
+} // end anonymous namespace
+
+bool Rewriter::overwriteChangedFiles() {
+  bool AllWritten = true;
+  for (buffer_iterator I = buffer_begin(), E = buffer_end(); I != E; ++I) {
+    const FileEntry *Entry =
+        getSourceMgr().getFileEntryForID(I->first);
+    AtomicallyMovedFile File(getSourceMgr().getDiagnostics(), Entry->getName(),
+                             AllWritten);
+    if (File.ok()) {
+      I->second.write(File.getStream());
+    }
+  }
+  return !AllWritten;
+}

external/llvm-project/clang/lib/Rewrite/TokenRewriter.cpp

@@ -0,0 +1,99 @@
+//===--- TokenRewriter.cpp - Token-based code rewriting interface ---------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+//  This file implements the TokenRewriter class, which is used for code
+//  transformations.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Rewrite/Core/TokenRewriter.h"
+#include "clang/Basic/SourceManager.h"
+#include "clang/Lex/Lexer.h"
+#include "clang/Lex/ScratchBuffer.h"
+using namespace clang;
+
+TokenRewriter::TokenRewriter(FileID FID, SourceManager &SM,
+                             const LangOptions &LangOpts) {
+  ScratchBuf.reset(new ScratchBuffer(SM));
+
+  // Create a lexer to lex all the tokens of the main file in raw mode.
+  const llvm::MemoryBuffer *FromFile = SM.getBuffer(FID);
+  Lexer RawLex(FID, FromFile, SM, LangOpts);
+
+  // Return all comments and whitespace as tokens.
+  RawLex.SetKeepWhitespaceMode(true);
+
+  // Lex the file, populating our datastructures.
+  Token RawTok;
+  RawLex.LexFromRawLexer(RawTok);
+  while (RawTok.isNot(tok::eof)) {
+#if 0
+    if (Tok.is(tok::raw_identifier)) {
+      // Look up the identifier info for the token.  This should use
+      // IdentifierTable directly instead of PP.
+      PP.LookUpIdentifierInfo(Tok);
+    }
+#endif
+
+    AddToken(RawTok, TokenList.end());
+    RawLex.LexFromRawLexer(RawTok);
+  }
+}
+
+TokenRewriter::~TokenRewriter() {
+}
+
+
+/// RemapIterator - Convert from token_iterator (a const iterator) to
+/// TokenRefTy (a non-const iterator).
+TokenRewriter::TokenRefTy TokenRewriter::RemapIterator(token_iterator I) {
+  if (I == token_end()) return TokenList.end();
+
+  // FIXME: This is horrible, we should use our own list or something to avoid
+  // this.
+  std::map<SourceLocation, TokenRefTy>::iterator MapIt =
+    TokenAtLoc.find(I->getLocation());
+  assert(MapIt != TokenAtLoc.end() && "iterator not in rewriter?");
+  return MapIt->second;
+}
+
+
+/// AddToken - Add the specified token into the Rewriter before the other
+/// position.
+TokenRewriter::TokenRefTy
+TokenRewriter::AddToken(const Token &T, TokenRefTy Where) {
+  Where = TokenList.insert(Where, T);
+
+  bool InsertSuccess = TokenAtLoc.insert(std::make_pair(T.getLocation(),
+                                                        Where)).second;
+  assert(InsertSuccess && "Token location already in rewriter!");
+  (void)InsertSuccess;
+  return Where;
+}
+
+
+TokenRewriter::token_iterator
+TokenRewriter::AddTokenBefore(token_iterator I, const char *Val) {
+  unsigned Len = strlen(Val);
+
+  // Plop the string into the scratch buffer, then create a token for this
+  // string.
+  Token Tok;
+  Tok.startToken();
+  const char *Spelling;
+  Tok.setLocation(ScratchBuf->getToken(Val, Len, Spelling));
+  Tok.setLength(Len);
+
+  // TODO: Form a whole lexer around this and relex the token!  For now, just
+  // set kind to tok::unknown.
+  Tok.setKind(tok::unknown);
+
+  return AddToken(Tok, RemapIterator(I));
+}
+