--- /dev/null
+//===--- RewriteRope.h - Rope specialized for rewriter ----------*- C++ -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file was developed by Chris Lattner and is distributed under
+// the University of Illinois Open Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines the RewriteRope class, which is a powerful string class.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_REWRITEROPE_H
+#define LLVM_CLANG_REWRITEROPE_H
+
+#include "llvm/ADT/iterator"
+#include <vector>
+
+
+namespace clang {
+
+struct RopeRefCountString {
+ unsigned RefCount;
+ char Data[1]; // Variable sized.
+};
+
+struct RopePiece {
+ RopeRefCountString *StrData;
+ unsigned StartOffs;
+ unsigned EndOffs;
+
+ RopePiece(RopeRefCountString *Str, unsigned Start, unsigned End)
+ : StrData(Str), StartOffs(Start), EndOffs(End) {
+ StrData->RefCount++;
+ }
+
+ ~RopePiece() {
+ if (--StrData->RefCount == 0)
+ delete [] (char*)StrData;
+ }
+
+ const char &operator[](unsigned Offset) const {
+ return StrData->Data[Offset+StartOffs];
+ }
+ char &operator[](unsigned Offset) {
+ return StrData->Data[Offset+StartOffs];
+ }
+
+ unsigned size() const { return EndOffs-StartOffs; }
+};
+
+class RewriteRope;
+
+template <typename CharType, typename PieceType>
+class RewriteRopeIterator :
+ public std::iterator<std::random_access_iterator_tag, CharType, ptrdiff_t> {
+ PieceType *CurPiece;
+ unsigned CurChar;
+ friend class RewriteRope;
+public:
+ RewriteRopeIterator(PieceType *curPiece, unsigned curChar)
+ : CurPiece(curPiece), CurChar(curChar) {}
+
+ CharType &operator*() const {
+ return (**CurPiece)[CurChar];
+ }
+
+ bool operator==(const RewriteRopeIterator &RHS) const {
+ return CurPiece == RHS.CurPiece && CurChar == RHS.CurChar;
+ }
+ bool operator!=(const RewriteRopeIterator &RHS) const {
+ return !operator==(RHS);
+ }
+
+ inline RewriteRopeIterator& operator++() { // Preincrement
+ if (CurChar+1 < (*CurPiece)->size())
+ ++CurChar;
+ else {
+ CurChar = 0;
+ ++CurPiece;
+ }
+ return *this;
+ }
+
+ inline RewriteRopeIterator operator++(int) { // Postincrement
+ RewriteRopeIterator tmp = *this; ++*this; return tmp;
+ }
+
+ RewriteRopeIterator operator+(int Offset) const {
+ assert(Offset >= 0 && "FIXME: Only handle forward case so far!");
+
+ PieceType *Piece = CurPiece;
+ unsigned Char = CurChar;
+ while (Char+Offset >= (*Piece)->size()) {
+ Offset -= (*Piece)->size()-Char;
+ ++Piece;
+ Char = 0;
+ }
+ Char += Offset;
+ return RewriteRopeIterator(Piece, Char);
+ }
+
+ ptrdiff_t operator-(const RewriteRopeIterator &RHS) const {
+ if (CurPiece < RHS.CurPiece ||
+ (CurPiece == RHS.CurPiece && CurChar < RHS.CurChar))
+ return -RHS.operator-(*this);
+
+ PieceType *Piece = RHS.CurPiece;
+ unsigned Char = RHS.CurChar;
+
+ unsigned Offset = 0;
+ while (Piece != CurPiece) {
+ Offset += (*Piece)->size()-Char;
+ Char = 0;
+ ++Piece;
+ }
+
+ return Offset + CurChar-Char;
+ }
+};
+
+
+
+/// RewriteRope - A powerful string class, todo generalize this.
+class RewriteRope {
+ std::vector<RopePiece*> Chunks;
+ unsigned CurSize;
+public:
+ RewriteRope() : CurSize(0) {}
+ ~RewriteRope() { clear(); }
+
+ typedef RewriteRopeIterator<char, RopePiece*> iterator;
+ typedef RewriteRopeIterator<const char, RopePiece* const> const_iterator;
+ iterator begin() {
+ if (Chunks.empty()) return iterator(0,0);
+ return iterator(&Chunks[0], 0);
+ }
+ iterator end() {
+ if (Chunks.empty()) return iterator(0,0);
+ return iterator(&Chunks[0]+Chunks.size(), 0);
+ }
+
+ const_iterator begin() const {
+ if (Chunks.empty()) return const_iterator(0,0);
+ return const_iterator(&Chunks[0], 0);
+ }
+ const_iterator end() const {
+ if (Chunks.empty()) return const_iterator(0,0);
+ return const_iterator(&Chunks[0]+Chunks.size(), 0);
+ }
+
+
+ unsigned size() const { return CurSize; }
+
+ void clear() {
+ for (unsigned i = 0, e = Chunks.size(); i != e; ++i)
+ delete Chunks[i];
+ Chunks.clear();
+ CurSize = 0;
+ }
+
+ void assign(const char *Start, const char *End) {
+ clear();
+ Chunks.push_back(new RopePiece(MakeRopeString(Start, End), 0,
+ End-Start));
+ CurSize = End-Start;
+ }
+
+ void insert(iterator Loc, const char *Start, const char *End) {
+ if (Start == End) return;
+
+ unsigned ChunkNo = SplitAt(Loc);
+
+ RopeRefCountString *Str = MakeRopeString(Start, End);
+ Chunks.insert(Chunks.begin()+ChunkNo, new RopePiece(Str, 0, End-Start));
+ CurSize += End-Start;
+ }
+
+ void erase(iterator Start, iterator End) {
+ if (Start == End) return;
+
+ unsigned StartChunkIdx = getChunkIdx(Start);
+ unsigned EndChunkIdx = getChunkIdx(End);
+
+ // If erase is localized within the same chunk, this is a degenerate case.
+ if (StartChunkIdx == EndChunkIdx) {
+ RopePiece *Chunk = Chunks[StartChunkIdx];
+ unsigned NumDel = End.CurChar-Start.CurChar;
+ CurSize -= NumDel;
+
+ // If deleting from start of chunk, just adjust range.
+ if (Start.CurChar == 0) {
+ if (Chunk->EndOffs != End.CurChar) {
+ Chunk->StartOffs += NumDel;
+ } else {
+ // Deleting entire chunk, remove it.
+ delete Chunk;
+ Chunks.erase(Chunks.begin()+StartChunkIdx);
+ }
+ return;
+ }
+
+ // If deleting to the end of chunk, just adjust range.
+ if (End.CurChar == Chunk->size()) {
+ Chunk->EndOffs -= NumDel;
+ return;
+ }
+
+ // If deleting the middle of a chunk, split this chunk and adjust the end
+ // piece.
+ unsigned NewIdx = SplitAt(Start);
+ Chunk = Chunks[NewIdx];
+ Chunk->StartOffs += End.CurChar-Start.CurChar;
+
+ return;
+ }
+
+
+ // Otherwise, the start chunk and the end chunk are different.
+
+ // Delete the end of the start chunk. If it is the whole thing, remove it.
+ {
+ RopePiece *StartChunk = Chunks[StartChunkIdx];
+ unsigned NumDel = StartChunk->size()-Start.CurChar;
+ CurSize -= NumDel;
+ if (Start.CurChar == 0) {
+ // Delete the whole chunk.
+ delete StartChunk;
+ Chunks.erase(Chunks.begin()+StartChunkIdx);
+ --EndChunkIdx;
+ } else {
+ // Otherwise, just move the end of chunk marker up.
+ StartChunk->EndOffs -= NumDel;
+ ++StartChunkIdx;
+ }
+ }
+
+ // If deleting a span of chunks, nuke them all now.
+ while (StartChunkIdx != EndChunkIdx) {
+ CurSize -= Chunks[StartChunkIdx]->size();
+ delete Chunks[StartChunkIdx];
+ Chunks.erase(Chunks.begin()+StartChunkIdx);
+ --EndChunkIdx;
+ }
+
+ // Finally, erase the start of the end chunk if appropriate.
+ if (End.CurChar != 0) {
+ RopePiece *EndChunk = Chunks[EndChunkIdx];
+ EndChunk->StartOffs += End.CurChar;
+ CurSize -= End.CurChar;
+ }
+ }
+
+private:
+ RopeRefCountString *MakeRopeString(const char *Start, const char *End) {
+ unsigned Size = End-Start+sizeof(RopeRefCountString)-1;
+ RopeRefCountString *Res =
+ reinterpret_cast<RopeRefCountString *>(new char[Size]);
+ Res->RefCount = 0;
+ memcpy(Res->Data, Start, End-Start);
+ return Res;
+ }
+
+ unsigned getChunkIdx(iterator Loc) const {
+ // Return the loc idx of the specified chunk, handling empty ropes.
+ return Loc.CurPiece == 0 ? 0 : Loc.CurPiece - &Chunks[0];
+ }
+
+ /// SplitAt - If the specified iterator position has a non-zero character
+ /// number, split the specified buffer up. This guarantees that the specified
+ /// iterator is at the start of a chunk. Return the chunk it is at the start
+ /// of.
+ unsigned SplitAt(iterator Loc) {
+ unsigned ChunkIdx = getChunkIdx(Loc);
+
+ // If the specified position is at the start of a piece, return it.
+ if (Loc.CurChar == 0)
+ return ChunkIdx;
+
+ // Otherwise, we have to split the specified piece in half, inserting the
+ // new piece into the vector of pieces.
+ RopePiece *CurPiece = *Loc.CurPiece;
+
+ // Make a new piece for the prefix part.
+ RopePiece *NewPiece = new RopePiece(CurPiece->StrData, CurPiece->StartOffs,
+ CurPiece->StartOffs+Loc.CurChar);
+
+ // Make the current piece refer the suffix part.
+ CurPiece->StartOffs += Loc.CurChar;
+
+ // Insert the new piece.
+ Chunks.insert(Chunks.begin()+ChunkIdx, NewPiece);
+
+ // Return the old chunk, which is the suffix.
+ return ChunkIdx+1;
+ }
+};
+
+} // end namespace clang
+
+#endif
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