Merge "Update prebuilt Clang to r353983." into p9.0HEADp9.0-backupp9.0

1 files changed, 214 insertions, 0 deletions

diff --git a/clang-r353983/include/clang/Rewrite/Core/RewriteRope.h b/clang-r353983/include/clang/Rewrite/Core/RewriteRope.h
new file mode 100644
index 00000000..039927c4
--- /dev/null
+++ b/clang-r353983/include/clang/Rewrite/Core/RewriteRope.h
@@ -0,0 +1,214 @@
+//===- RewriteRope.h - Rope specialized for rewriter ------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+//  This file defines the RewriteRope class, which is a powerful string class.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_REWRITE_CORE_REWRITEROPE_H
+#define LLVM_CLANG_REWRITE_CORE_REWRITEROPE_H
+
+#include "llvm/ADT/IntrusiveRefCntPtr.h"
+#include "llvm/ADT/StringRef.h"
+#include <cassert>
+#include <cstddef>
+#include <iterator>
+#include <utility>
+
+namespace clang {
+
+  //===--------------------------------------------------------------------===//
+  // RopeRefCountString Class
+  //===--------------------------------------------------------------------===//
+
+  /// RopeRefCountString - This struct is allocated with 'new char[]' from the
+  /// heap, and represents a reference counted chunk of string data.  When its
+  /// ref count drops to zero, it is delete[]'d.  This is primarily managed
+  /// through the RopePiece class below.
+  struct RopeRefCountString {
+    unsigned RefCount;
+    char Data[1];  //  Variable sized.
+
+    void Retain() { ++RefCount; }
+
+    void Release() {
+      assert(RefCount > 0 && "Reference count is already zero.");
+      if (--RefCount == 0)
+        delete [] (char*)this;
+    }
+  };
+
+  //===--------------------------------------------------------------------===//
+  // RopePiece Class
+  //===--------------------------------------------------------------------===//
+
+  /// RopePiece - This class represents a view into a RopeRefCountString object.
+  /// This allows references to string data to be efficiently chopped up and
+  /// moved around without having to push around the string data itself.
+  ///
+  /// For example, we could have a 1M RopePiece and want to insert something
+  /// into the middle of it.  To do this, we split it into two RopePiece objects
+  /// that both refer to the same underlying RopeRefCountString (just with
+  /// different offsets) which is a nice constant time operation.
+  struct RopePiece {
+    llvm::IntrusiveRefCntPtr<RopeRefCountString> StrData;
+    unsigned StartOffs = 0;
+    unsigned EndOffs = 0;
+
+    RopePiece() = default;
+    RopePiece(llvm::IntrusiveRefCntPtr<RopeRefCountString> Str, unsigned Start,
+              unsigned End)
+        : StrData(std::move(Str)), StartOffs(Start), EndOffs(End) {}
+
+    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; }
+  };
+
+  //===--------------------------------------------------------------------===//
+  // RopePieceBTreeIterator Class
+  //===--------------------------------------------------------------------===//
+
+  /// RopePieceBTreeIterator - This class provides read-only forward iteration
+  /// over bytes that are in a RopePieceBTree.  This first iterates over bytes
+  /// in a RopePiece, then iterates over RopePiece's in a RopePieceBTreeLeaf,
+  /// then iterates over RopePieceBTreeLeaf's in a RopePieceBTree.
+  class RopePieceBTreeIterator :
+      public std::iterator<std::forward_iterator_tag, const char, ptrdiff_t> {
+    /// CurNode - The current B+Tree node that we are inspecting.
+    const void /*RopePieceBTreeLeaf*/ *CurNode = nullptr;
+
+    /// CurPiece - The current RopePiece in the B+Tree node that we're
+    /// inspecting.
+    const RopePiece *CurPiece = nullptr;
+
+    /// CurChar - The current byte in the RopePiece we are pointing to.
+    unsigned CurChar = 0;
+
+  public:
+    RopePieceBTreeIterator() = default;
+    RopePieceBTreeIterator(const void /*RopePieceBTreeNode*/ *N);
+
+    char operator*() const {
+      return (*CurPiece)[CurChar];
+    }
+
+    bool operator==(const RopePieceBTreeIterator &RHS) const {
+      return CurPiece == RHS.CurPiece && CurChar == RHS.CurChar;
+    }
+    bool operator!=(const RopePieceBTreeIterator &RHS) const {
+      return !operator==(RHS);
+    }
+
+    RopePieceBTreeIterator& operator++() {   // Preincrement
+      if (CurChar+1 < CurPiece->size())
+        ++CurChar;
+      else
+        MoveToNextPiece();
+      return *this;
+    }
+
+    RopePieceBTreeIterator operator++(int) { // Postincrement
+      RopePieceBTreeIterator tmp = *this; ++*this; return tmp;
+    }
+
+    llvm::StringRef piece() const {
+      return llvm::StringRef(&(*CurPiece)[0], CurPiece->size());
+    }
+
+    void MoveToNextPiece();
+  };
+
+  //===--------------------------------------------------------------------===//
+  // RopePieceBTree Class
+  //===--------------------------------------------------------------------===//
+
+  class RopePieceBTree {
+    void /*RopePieceBTreeNode*/ *Root;
+
+  public:
+    RopePieceBTree();
+    RopePieceBTree(const RopePieceBTree &RHS);
+    RopePieceBTree &operator=(const RopePieceBTree &) = delete;
+    ~RopePieceBTree();
+
+    using iterator = RopePieceBTreeIterator;
+
+    iterator begin() const { return iterator(Root); }
+    iterator end() const { return iterator(); }
+    unsigned size() const;
+    unsigned empty() const { return size() == 0; }
+
+    void clear();
+
+    void insert(unsigned Offset, const RopePiece &R);
+
+    void erase(unsigned Offset, unsigned NumBytes);
+  };
+
+  //===--------------------------------------------------------------------===//
+  // RewriteRope Class
+  //===--------------------------------------------------------------------===//
+
+/// RewriteRope - A powerful string class.  This class supports extremely
+/// efficient insertions and deletions into the middle of it, even for
+/// ridiculously long strings.
+class RewriteRope {
+  RopePieceBTree Chunks;
+
+  /// We allocate space for string data out of a buffer of size AllocChunkSize.
+  /// This keeps track of how much space is left.
+  llvm::IntrusiveRefCntPtr<RopeRefCountString> AllocBuffer;
+  enum { AllocChunkSize = 4080 };
+  unsigned AllocOffs = AllocChunkSize;
+
+public:
+  RewriteRope() = default;
+  RewriteRope(const RewriteRope &RHS) : Chunks(RHS.Chunks) {}
+
+  using iterator = RopePieceBTree::iterator;
+  using const_iterator = RopePieceBTree::iterator;
+
+  iterator begin() const { return Chunks.begin(); }
+  iterator end() const { return Chunks.end(); }
+  unsigned size() const { return Chunks.size(); }
+
+  void clear() {
+    Chunks.clear();
+  }
+
+  void assign(const char *Start, const char *End) {
+    clear();
+    if (Start != End)
+      Chunks.insert(0, MakeRopeString(Start, End));
+  }
+
+  void insert(unsigned Offset, const char *Start, const char *End) {
+    assert(Offset <= size() && "Invalid position to insert!");
+    if (Start == End) return;
+    Chunks.insert(Offset, MakeRopeString(Start, End));
+  }
+
+  void erase(unsigned Offset, unsigned NumBytes) {
+    assert(Offset+NumBytes <= size() && "Invalid region to erase!");
+    if (NumBytes == 0) return;
+    Chunks.erase(Offset, NumBytes);
+  }
+
+private:
+  RopePiece MakeRopeString(const char *Start, const char *End);
+};
+
+} // namespace clang
+
+#endif // LLVM_CLANG_REWRITE_CORE_REWRITEROPE_H