//===- RewriteBuffer.h - Buffer rewriting interface -------------*- 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
 
//
 
//===----------------------------------------------------------------------===//
 
 
 
#ifndef LLVM_CLANG_REWRITE_CORE_REWRITEBUFFER_H
 
#define LLVM_CLANG_REWRITE_CORE_REWRITEBUFFER_H
 
 
 
#include "clang/Basic/LLVM.h"
 
#include "clang/Rewrite/Core/DeltaTree.h"
 
#include "clang/Rewrite/Core/RewriteRope.h"
 
#include "llvm/ADT/StringRef.h"
 
 
 
namespace clang {
 
 
 
/// RewriteBuffer - As code is rewritten, SourceBuffer's from the original
 
/// input with modifications get a new RewriteBuffer associated with them.  The
 
/// RewriteBuffer captures the modified text itself as well as information used
 
/// to map between SourceLocation's in the original input and offsets in the
 
/// RewriteBuffer.  For example, if text is inserted into the buffer, any
 
/// locations after the insertion point have to be mapped.
 
class RewriteBuffer {
 
  friend class Rewriter;
 
 
 
  /// Deltas - Keep track of all the deltas in the source code due to insertions
 
  /// and deletions.
 
  DeltaTree Deltas;
 
 
 
  RewriteRope Buffer;
 
 
 
public:
 
  using iterator = RewriteRope::const_iterator;
 
 
 
  iterator begin() const { return Buffer.begin(); }
 
  iterator end() const { return Buffer.end(); }
 
  unsigned size() const { return Buffer.size(); }
 
 
 
  /// Initialize - Start this rewrite buffer out with a copy of the unmodified
 
  /// input buffer.
 
  void Initialize(const char *BufStart, const char *BufEnd) {
 
    Buffer.assign(BufStart, BufEnd);
 
  }
 
  void Initialize(StringRef Input) {
 
    Initialize(Input.begin(), Input.end());
 
  }
 
 
 
  /// Write to \p Stream the result of applying all changes to the
 
  /// original buffer.
 
  /// Note that it isn't safe to use this function to overwrite memory mapped
 
  /// files in-place (PR17960). Consider using a higher-level utility such as
 
  /// Rewriter::overwriteChangedFiles() instead.
 
  ///
 
  /// The original buffer is not actually changed.
 
  raw_ostream &write(raw_ostream &Stream) const;
 
 
 
  /// RemoveText - Remove the specified text.
 
  void RemoveText(unsigned OrigOffset, unsigned Size,
 
                  bool removeLineIfEmpty = false);
 
 
 
  /// InsertText - Insert some text at the specified point, where the offset in
 
  /// the buffer is specified relative to the original SourceBuffer.  The
 
  /// text is inserted after the specified location.
 
  void InsertText(unsigned OrigOffset, StringRef Str,
 
                  bool InsertAfter = true);
 
 
 
 
 
  /// InsertTextBefore - Insert some text before the specified point, where the
 
  /// offset in the buffer is specified relative to the original
 
  /// SourceBuffer. The text is inserted before the specified location.  This is
 
  /// method is the same as InsertText with "InsertAfter == false".
 
  void InsertTextBefore(unsigned OrigOffset, StringRef Str) {
 
    InsertText(OrigOffset, Str, false);
 
  }
 
 
 
  /// InsertTextAfter - Insert some text at the specified point, where the
 
  /// offset in the buffer is specified relative to the original SourceBuffer.
 
  /// The text is inserted after the specified location.
 
  void InsertTextAfter(unsigned OrigOffset, StringRef Str) {
 
    InsertText(OrigOffset, Str);
 
  }
 
 
 
  /// 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 ReplaceText(unsigned OrigOffset, unsigned OrigLength,
 
                   StringRef NewStr);
 
 
 
private:
 
  /// getMappedOffset - Given an offset into the original SourceBuffer that this
 
  /// RewriteBuffer is based on, map it into the offset space of the
 
  /// RewriteBuffer.  If AfterInserts is true and if the OrigOffset indicates a
 
  /// position where text is inserted, the location returned will be after any
 
  /// inserted text at the position.
 
  unsigned getMappedOffset(unsigned OrigOffset,
 
                           bool AfterInserts = false) const{
 
    return Deltas.getDeltaAt(2*OrigOffset+AfterInserts)+OrigOffset;
 
  }
 
 
 
  /// AddInsertDelta - When an insertion is made at a position, this
 
  /// method is used to record that information.
 
  void AddInsertDelta(unsigned OrigOffset, int Change) {
 
    return Deltas.AddDelta(2*OrigOffset, Change);
 
  }
 
 
 
  /// AddReplaceDelta - When a replacement/deletion is made at a position, this
 
  /// method is used to record that information.
 
  void AddReplaceDelta(unsigned OrigOffset, int Change) {
 
    return Deltas.AddDelta(2*OrigOffset+1, Change);
 
  }
 
};
 
 
 
} // namespace clang
 
 
 
#endif // LLVM_CLANG_REWRITE_CORE_REWRITEBUFFER_H