//===- Rewriter.h - Code 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

//

//===----------------------------------------------------------------------===//

//

//  This file defines the Rewriter class, which is used for code

//  transformations.

//

//===----------------------------------------------------------------------===//

#ifndef LLVM_CLANG_REWRITE_CORE_REWRITER_H

#define LLVM_CLANG_REWRITE_CORE_REWRITER_H

#include "clang/Basic/LLVM.h"

#include "clang/Basic/SourceLocation.h"

#include "clang/Rewrite/Core/RewriteBuffer.h"

#include "llvm/ADT/StringRef.h"

#include <map>

#include <string>

namespace clang {

class LangOptions;

class SourceManager;

/// Rewriter - This is the main interface to the rewrite buffers.  Its primary

/// job is to dispatch high-level requests to the low-level RewriteBuffers that

/// are involved.

class Rewriter {

  SourceManager *SourceMgr = nullptr;

  const LangOptions *LangOpts = nullptr;

  std::map<FileID, RewriteBuffer> RewriteBuffers;

public:

  struct RewriteOptions {

    /// Given a source range, true to include previous inserts at the

    /// beginning of the range as part of the range itself (true by default).

    bool IncludeInsertsAtBeginOfRange = true;

    /// Given a source range, true to include previous inserts at the

    /// end of the range as part of the range itself (true by default).

    bool IncludeInsertsAtEndOfRange = true;

    /// If true and removing some text leaves a blank line

    /// also remove the empty line (false by default).

    ///

    /// FIXME: This sometimes corrupts the file's rewrite buffer due to

    /// incorrect indexing in the implementation (see the FIXME in

    /// clang::RewriteBuffer::RemoveText).  Moreover, it's inefficient because

    /// it must scan the buffer from the beginning to find the start of the

    /// line.  When feasible, it's better for the caller to check for a blank

    /// line and then, if found, expand the removal range to include it.

    /// Checking for a blank line is easy if, for example, the caller can

    /// guarantee this is the first edit of a line.  In that case, it can just

    /// scan before and after the removal range until the next newline or

    /// begin/end of the input.

    bool RemoveLineIfEmpty = false;

    RewriteOptions() {}

  };

  using buffer_iterator = std::map<FileID, RewriteBuffer>::iterator;

  using const_buffer_iterator = std::map<FileID, RewriteBuffer>::const_iterator;

  explicit Rewriter() = default;

  explicit Rewriter(SourceManager &SM, const LangOptions &LO)

      : SourceMgr(&SM), LangOpts(&LO) {}

  void setSourceMgr(SourceManager &SM, const LangOptions &LO) {

    SourceMgr = &SM;

    LangOpts = &LO;

  }

  SourceManager &getSourceMgr() const { return *SourceMgr; }

  const LangOptions &getLangOpts() const { return *LangOpts; }

  /// isRewritable - Return true if this location is a raw file location, which

  /// is rewritable.  Locations from macros, etc are not rewritable.

  static bool isRewritable(SourceLocation Loc) {

    return Loc.isFileID();

  }

  /// getRangeSize - Return the size in bytes of the specified range if they

  /// are in the same file.  If not, this returns -1.

  int getRangeSize(SourceRange Range,

                   RewriteOptions opts = RewriteOptions()) const;

  int getRangeSize(const CharSourceRange &Range,

                   RewriteOptions opts = RewriteOptions()) const;

  /// 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 getRewrittenText(CharSourceRange Range) const;

  /// 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 getRewrittenText(SourceRange Range) const {

    return getRewrittenText(CharSourceRange::getTokenRange(Range));

  }

  /// InsertText - Insert the specified string at the specified location in the

  /// original buffer.  This method returns true (and does nothing) if the input

  /// location was not rewritable, false otherwise.

  ///

  /// \param indentNewLines if true new lines in the string are indented

  /// using the indentation of the source line in position \p Loc.

  bool InsertText(SourceLocation Loc, StringRef Str,

                  bool InsertAfter = true, bool indentNewLines = false);

  /// InsertTextAfter - Insert the specified string at the specified location in

  ///  the original buffer.  This method returns true (and does nothing) if

  ///  the input location was not rewritable, false otherwise.  Text is

  ///  inserted after any other text that has been previously inserted

  ///  at the some point (the default behavior for InsertText).

  bool InsertTextAfter(SourceLocation Loc, StringRef Str) {

    return InsertText(Loc, Str);

  }

  /// Insert the specified string after the token in the

  /// specified location.

  bool InsertTextAfterToken(SourceLocation Loc, StringRef Str);

  /// InsertText - Insert the specified string at the specified location in the

  /// original buffer.  This method returns true (and does nothing) if the input

  /// location was not rewritable, false otherwise.  Text is

  /// inserted before any other text that has been previously inserted

  /// at the some point.

  bool InsertTextBefore(SourceLocation Loc, StringRef Str) {

    return InsertText(Loc, Str, false);

  }

  /// RemoveText - Remove the specified text region.

  bool RemoveText(SourceLocation Start, unsigned Length,

                  RewriteOptions opts = RewriteOptions());

  /// Remove the specified text region.

  bool RemoveText(CharSourceRange range,

                  RewriteOptions opts = RewriteOptions()) {

    return RemoveText(range.getBegin(), getRangeSize(range, opts), opts);

  }

  /// Remove the specified text region.

  bool RemoveText(SourceRange range, RewriteOptions opts = RewriteOptions()) {

    return RemoveText(range.getBegin(), getRangeSize(range, opts), opts);

  }

  /// 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 ReplaceText(SourceLocation Start, unsigned OrigLength,

                   StringRef NewStr);

  /// 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 ReplaceText(CharSourceRange range, StringRef NewStr) {

    return ReplaceText(range.getBegin(), getRangeSize(range), NewStr);

  }

  /// 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 ReplaceText(SourceRange range, StringRef NewStr) {

    return ReplaceText(range.getBegin(), getRangeSize(range), NewStr);

  }

  /// 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 ReplaceText(SourceRange range, SourceRange replacementRange);

  /// Increase indentation for the lines between the given source range.

  /// To determine what the indentation should be, 'parentIndent' is used

  /// that should be at a source location with an indentation one degree

  /// lower than the given range.

  bool IncreaseIndentation(CharSourceRange range, SourceLocation parentIndent);

  bool IncreaseIndentation(SourceRange range, SourceLocation parentIndent) {

    return IncreaseIndentation(CharSourceRange::getTokenRange(range),

                               parentIndent);

  }

  /// getEditBuffer - This is like getRewriteBufferFor, but always returns a

  /// buffer, and allows you to write on it directly.  This is useful if you

  /// want efficient low-level access to apis for scribbling on one specific

  /// FileID's buffer.

  RewriteBuffer &getEditBuffer(FileID FID);

  /// getRewriteBufferFor - Return the rewrite buffer for the specified FileID.

  /// If no modification has been made to it, return null.

  const RewriteBuffer *getRewriteBufferFor(FileID FID) const {

    std::map<FileID, RewriteBuffer>::const_iterator I =

      RewriteBuffers.find(FID);

    return I == RewriteBuffers.end() ? 
nullptr0
 : &I->second;

  }

  // Iterators over rewrite buffers.

  buffer_iterator buffer_begin() { return RewriteBuffers.begin(); }

  buffer_iterator buffer_end() { return RewriteBuffers.end(); }

  const_buffer_iterator buffer_begin() const { return RewriteBuffers.begin(); }

  const_buffer_iterator buffer_end() const { return RewriteBuffers.end(); }

  /// overwriteChangedFiles - Save all changed files to disk.

  ///

  /// Returns true if any files were not saved successfully.

  /// Outputs diagnostics via the source manager's diagnostic engine

  /// in case of an error.

  bool overwriteChangedFiles();

private:

  unsigned getLocationOffsetAndFileID(SourceLocation Loc, FileID &FID) const;

};

} // namespace clang

#endif // LLVM_CLANG_REWRITE_CORE_REWRITER_H