//===--- Transformer.cpp - Transformer library implementation ---*- 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

//

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

#include "clang/Tooling/Transformer/Transformer.h"

#include "clang/ASTMatchers/ASTMatchFinder.h"

#include "clang/ASTMatchers/ASTMatchersInternal.h"

#include "clang/Basic/SourceLocation.h"

#include "clang/Tooling/Refactoring/AtomicChange.h"

#include "llvm/Support/Error.h"

#include <map>

#include <utility>

#include <vector>

namespace clang {

namespace tooling {

using ::clang::ast_matchers::MatchFinder;

namespace detail {

void TransformerImpl::onMatch(

    const ast_matchers::MatchFinder::MatchResult &Result) {

  if (Result.Context->getDiagnostics().hasErrorOccurred())

    return;

  onMatchImpl(Result);

}

llvm::Expected<llvm::SmallVector<AtomicChange, 1>>

TransformerImpl::convertToAtomicChanges(

    const llvm::SmallVectorImpl<transformer::Edit> &Edits,

    const MatchFinder::MatchResult &Result) {

  // Group the transformations, by file, into AtomicChanges, each anchored by

  // the location of the first change in that file.

  std::map<FileID, AtomicChange> ChangesByFileID;

  for (const auto &T : Edits) {

    auto ID = Result.SourceManager->getFileID(T.Range.getBegin());

    auto Iter = ChangesByFileID

                    .emplace(ID, AtomicChange(*Result.SourceManager,

                                              T.Range.getBegin(), T.Metadata))

                    .first;

    auto &AC = Iter->second;

    switch (T.Kind) {

    case transformer::EditKind::Range:

      if (auto Err =

              AC.replace(*Result.SourceManager, T.Range, T.Replacement)) {

        return std::move(Err);

      }

      break;

    case transformer::EditKind::AddInclude:

      AC.addHeader(T.Replacement);

      break;

    }

  }

  llvm::SmallVector<AtomicChange, 1> Changes;

  Changes.reserve(ChangesByFileID.size());

  for (auto &IDChangePair : ChangesByFileID)

    Changes.push_back(std::move(IDChangePair.second));

  return Changes;

}

} // namespace detail

void Transformer::registerMatchers(MatchFinder *MatchFinder) {

  for (auto &Matcher : Impl->buildMatchers())

    MatchFinder->addDynamicMatcher(Matcher, this);

}

void Transformer::run(const MatchFinder::MatchResult &Result) {

  if (Result.Context->getDiagnostics().hasErrorOccurred())

    return;

  Impl->onMatch(Result);

}

} // namespace tooling

} // namespace clang