//===--- tools/extra/clang-tidy/ClangTidyDiagnosticConsumer.cpp ----------=== //
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
///
///  \file This file implements ClangTidyDiagnosticConsumer, ClangTidyMessage,
///  ClangTidyContext and ClangTidyError classes.
///
///  This tool uses the Clang Tooling infrastructure, see
///    http://clang.llvm.org/docs/HowToSetupToolingForLLVM.html
///  for details on setting it up with LLVM source tree.
///
//===----------------------------------------------------------------------===//

#include "ClangTidyDiagnosticConsumer.h"

#include "ClangTidyOptions.h"
#include "clang/Frontend/DiagnosticRenderer.h"
#include "llvm/ADT/SmallString.h"

#include <set>
#include <tuple>

namespace clang {
namespace tidy {

class ClangTidyDiagnosticRenderer : public DiagnosticRenderer {
public:
  ClangTidyDiagnosticRenderer(const LangOptions &LangOpts,
                              DiagnosticOptions *DiagOpts,
                              ClangTidyError &Error)
      : DiagnosticRenderer(LangOpts, DiagOpts), Error(Error) {}

protected:
  void emitDiagnosticMessage(SourceLocation Loc, PresumedLoc PLoc,
                             DiagnosticsEngine::Level Level, StringRef Message,
                             ArrayRef<CharSourceRange> Ranges,
                             const SourceManager *SM,
                             DiagOrStoredDiag Info) override {
    if (Level == DiagnosticsEngine::Ignored)
      return;
    ClangTidyMessage TidyMessage = Loc.isValid()
                                       ? ClangTidyMessage(Message, *SM, Loc)
                                       : ClangTidyMessage(Message);
    if (Level == DiagnosticsEngine::Note) {
      Error.Notes.push_back(TidyMessage);
      return;
    }
    assert(Error.Message.Message.empty() &&
           "Overwriting a diagnostic message");
    Error.Message = TidyMessage;
  }

  void emitDiagnosticLoc(SourceLocation Loc, PresumedLoc PLoc,
                         DiagnosticsEngine::Level Level,
                         ArrayRef<CharSourceRange> Ranges,
                         const SourceManager &SM) override {}

  void emitBasicNote(StringRef Message) override {
    Error.Notes.push_back(ClangTidyMessage(Message));
  }

  void emitCodeContext(SourceLocation Loc, DiagnosticsEngine::Level Level,
                       SmallVectorImpl<CharSourceRange> &Ranges,
                       ArrayRef<FixItHint> Hints,
                       const SourceManager &SM) override {
    assert(Loc.isValid());
    for (const auto &FixIt : Hints) {
      CharSourceRange Range = FixIt.RemoveRange;
      assert(Range.getBegin().isValid() && Range.getEnd().isValid() &&
             "Invalid range in the fix-it hint.");
      assert(Range.getBegin().isFileID() && Range.getEnd().isFileID() &&
             "Only file locations supported in fix-it hints.");

      Error.Fix.insert(tooling::Replacement(SM, Range, FixIt.CodeToInsert));
    }
  }

  void emitIncludeLocation(SourceLocation Loc, PresumedLoc PLoc,
                           const SourceManager &SM) override {}

  void emitImportLocation(SourceLocation Loc, PresumedLoc PLoc,
                          StringRef ModuleName,
                          const SourceManager &SM) override {}

  void emitBuildingModuleLocation(SourceLocation Loc, PresumedLoc PLoc,
                                  StringRef ModuleName,
                                  const SourceManager &SM) override {}

  void endDiagnostic(DiagOrStoredDiag D,
                     DiagnosticsEngine::Level Level) override {
    assert(!Error.Message.Message.empty() && "Message has not been set");
  }

private:
  ClangTidyError &Error;
};

ClangTidyMessage::ClangTidyMessage(StringRef Message) : Message(Message) {}

ClangTidyMessage::ClangTidyMessage(StringRef Message,
                                   const SourceManager &Sources,
                                   SourceLocation Loc)
    : Message(Message) {
  assert(Loc.isValid() && Loc.isFileID());
  FilePath = Sources.getFilename(Loc);
  FileOffset = Sources.getFileOffset(Loc);
}

ClangTidyError::ClangTidyError(StringRef CheckName)
    : CheckName(CheckName) {}

ChecksFilter::ChecksFilter(const ClangTidyOptions &Options)
    : EnableChecks(Options.EnableChecksRegex),
      DisableChecks(Options.DisableChecksRegex) {}

bool ChecksFilter::isCheckEnabled(StringRef Name) {
  return EnableChecks.match(Name) && !DisableChecks.match(Name);
}

ClangTidyContext::ClangTidyContext(SmallVectorImpl<ClangTidyError> *Errors,
                                   const ClangTidyOptions &Options)
    : Errors(Errors), DiagEngine(nullptr), Filter(Options) {}

DiagnosticBuilder ClangTidyContext::diag(
    StringRef CheckName, SourceLocation Loc, StringRef Description,
    DiagnosticIDs::Level Level /* = DiagnosticIDs::Warning*/) {
  assert(Loc.isValid());
  bool Invalid;
  const char *CharacterData =
      DiagEngine->getSourceManager().getCharacterData(Loc, &Invalid);
  if (!Invalid) {
    const char *P = CharacterData;
    while (*P != '\0' && *P != '\r' && *P != '\n')
      ++P;
    StringRef RestOfLine(CharacterData, P - CharacterData + 1);
    // FIXME: Handle /\bNOLINT\b(\([^)]*\))?/ as cpplint.py does.
    if (RestOfLine.find("NOLINT") != StringRef::npos)
      Level = DiagnosticIDs::Ignored;
  }
  unsigned ID = DiagEngine->getDiagnosticIDs()->getCustomDiagID(
      Level, (Description + " [" + CheckName + "]").str());
  if (CheckNamesByDiagnosticID.count(ID) == 0)
    CheckNamesByDiagnosticID.insert(std::make_pair(ID, CheckName.str()));
  return DiagEngine->Report(Loc, ID);
}

void ClangTidyContext::setDiagnosticsEngine(DiagnosticsEngine *Engine) {
  DiagEngine = Engine;
}

void ClangTidyContext::setSourceManager(SourceManager *SourceMgr) {
  DiagEngine->setSourceManager(SourceMgr);
}

/// \brief Store a \c ClangTidyError.
void ClangTidyContext::storeError(const ClangTidyError &Error) {
  Errors->push_back(Error);
}

StringRef ClangTidyContext::getCheckName(unsigned DiagnosticID) const {
  llvm::DenseMap<unsigned, std::string>::const_iterator I =
      CheckNamesByDiagnosticID.find(DiagnosticID);
  if (I != CheckNamesByDiagnosticID.end())
    return I->second;
  return "";
}

ClangTidyDiagnosticConsumer::ClangTidyDiagnosticConsumer(ClangTidyContext &Ctx)
    : Context(Ctx), LastErrorRelatesToUserCode(false) {
  IntrusiveRefCntPtr<DiagnosticOptions> DiagOpts = new DiagnosticOptions();
  Diags.reset(new DiagnosticsEngine(
      IntrusiveRefCntPtr<DiagnosticIDs>(new DiagnosticIDs), &*DiagOpts, this,
      /*ShouldOwnClient=*/false));
  Context.setDiagnosticsEngine(Diags.get());
}

void ClangTidyDiagnosticConsumer::finalizeLastError() {
  if (!LastErrorRelatesToUserCode && !Errors.empty())
    Errors.pop_back();
  LastErrorRelatesToUserCode = false;
}

void ClangTidyDiagnosticConsumer::HandleDiagnostic(
    DiagnosticsEngine::Level DiagLevel, const Diagnostic &Info) {
  if (DiagLevel == DiagnosticsEngine::Note) {
    assert(!Errors.empty() &&
           "A diagnostic note can only be appended to a message.");
  } else {
    finalizeLastError();
    StringRef WarningOption =
        Context.DiagEngine->getDiagnosticIDs()->getWarningOptionForDiag(
            Info.getID());
    std::string CheckName = !WarningOption.empty()
                                ? ("clang-diagnostic-" + WarningOption).str()
                                : Context.getCheckName(Info.getID()).str();

    Errors.push_back(ClangTidyError(CheckName));
  }

  // FIXME: Provide correct LangOptions for each file.
  LangOptions LangOpts;
  ClangTidyDiagnosticRenderer Converter(
      LangOpts, &Context.DiagEngine->getDiagnosticOptions(), Errors.back());
  SmallString<100> Message;
  Info.FormatDiagnostic(Message);
  SourceManager *Sources = nullptr;
  if (Info.hasSourceManager())
    Sources = &Info.getSourceManager();
  Converter.emitDiagnostic(
      Info.getLocation(), DiagLevel, Message, Info.getRanges(),
      llvm::makeArrayRef(Info.getFixItHints(), Info.getNumFixItHints()),
      Sources);

  // Let argument parsing-related warnings through.
  if (!Info.getLocation().isValid() ||
      !Diags->getSourceManager().isInSystemHeader(Info.getLocation())) {
    LastErrorRelatesToUserCode = true;
  }
}

struct LessClangTidyError {
  bool operator()(const ClangTidyError *LHS, const ClangTidyError *RHS) const {
    const ClangTidyMessage &M1 = LHS->Message;
    const ClangTidyMessage &M2 = RHS->Message;

    return std::tie(M1.FilePath, M1.FileOffset, M1.Message) <
           std::tie(M2.FilePath, M2.FileOffset, M2.Message);
  }
};

// Flushes the internal diagnostics buffer to the ClangTidyContext.
void ClangTidyDiagnosticConsumer::finish() {
  finalizeLastError();
  std::set<const ClangTidyError*, LessClangTidyError> UniqueErrors;
  for (const ClangTidyError &Error : Errors) {
    if (Context.getChecksFilter().isCheckEnabled(Error.CheckName))
      UniqueErrors.insert(&Error);
  }
  for (const ClangTidyError *Error : UniqueErrors)
    Context.storeError(*Error);
  Errors.clear();
}

} // namespace tidy
} // namespace clang