clang-tools-extra/clang-tidy/ClangTidyDiagnosticConsumer.h

//===--- ClangTidyDiagnosticConsumer.h - clang-tidy -------------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_CLANG_TIDY_DIAGNOSTIC_CONSUMER_H
#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_CLANG_TIDY_DIAGNOSTIC_CONSUMER_H

#include "clang/Basic/Diagnostic.h"
#include "clang/Basic/SourceManager.h"
#include "clang/Tooling/Refactoring.h"
#include "llvm/ADT/DenseMap.h"

namespace clang {

class CompilerInstance;
namespace ast_matchers {
class MatchFinder;
}
namespace tooling {
class CompilationDatabase;
}

namespace tidy {

/// \brief A message from a clang-tidy check.
///
/// Note that this is independent of a \c SourceManager.
struct ClangTidyMessage {
  ClangTidyMessage(StringRef Message = "");
  ClangTidyMessage(StringRef Message, const SourceManager &Sources,
                   SourceLocation Loc);
  std::string Message;
  std::string FilePath;
  unsigned FileOffset;
};

/// \brief A detected error complete with information to display diagnostic and
/// automatic fix.
///
/// This is used as an intermediate format to transport Diagnostics without a
/// dependency on a SourceManager.
///
/// FIXME: Make Diagnostics flexible enough to support this directly.
struct ClangTidyError {
  ClangTidyError(StringRef CheckName, const ClangTidyMessage &Message);

  std::string CheckName;
  ClangTidyMessage Message;
  tooling::Replacements Fix;
  SmallVector<ClangTidyMessage, 1> Notes;
};

/// \brief Every \c ClangTidyCheck reports errors through a \c DiagnosticEngine
/// provided by this context.
///
/// A \c ClangTidyCheck always has access to the active context to report
/// warnings like:
/// \code
/// Context->Diag(Loc, "Single-argument constructors must be explicit")
///     << FixItHint::CreateInsertion(Loc, "explicit ");
/// \endcode
class ClangTidyContext {
public:
  ClangTidyContext(SmallVectorImpl<ClangTidyError> *Errors)
      : Errors(Errors), DiagEngine(0) {}

  /// \brief Report any errors detected using this method.
  ///
  /// This is still under heavy development and will likely change towards using
  /// tablegen'd diagnostic IDs.
  /// FIXME: Figure out a way to manage ID spaces.
  DiagnosticBuilder diag(StringRef CheckName, SourceLocation Loc,
                         StringRef Message,
                         DiagnosticIDs::Level Level = DiagnosticIDs::Warning);

  /// \brief Sets the \c DiagnosticsEngine so that Diagnostics can be generated
  /// correctly.
  ///
  /// This is called from the \c ClangTidyCheck base class.
  void setDiagnosticsEngine(DiagnosticsEngine *Engine);

  /// \brief Sets the \c SourceManager of the used \c DiagnosticsEngine.
  ///
  /// This is called from the \c ClangTidyCheck base class.
  void setSourceManager(SourceManager *SourceMgr);

  /// \brief Returns the name of the clang-tidy check which produced this
  /// diagnostic ID.
  StringRef getCheckName(unsigned DiagnosticID) const;

private:
  friend class ClangTidyDiagnosticConsumer; // Calls storeError().

  /// \brief Store a \c ClangTidyError.
  void storeError(const ClangTidyError &Error);

  SmallVectorImpl<ClangTidyError> *Errors;
  DiagnosticsEngine *DiagEngine;
  llvm::DenseMap<unsigned, std::string> CheckNamesByDiagnosticID;
};

/// \brief A diagnostic consumer that turns each \c Diagnostic into a
/// \c SourceManager-independent \c ClangTidyError.
//
// FIXME: If we move away from unit-tests, this can be moved to a private
// implementation file.
class ClangTidyDiagnosticConsumer : public DiagnosticConsumer {
public:
  ClangTidyDiagnosticConsumer(ClangTidyContext &Ctx);

  // FIXME: The concept of converting between FixItHints and Replacements is
  // more generic and should be pulled out into a more useful Diagnostics
  // library.
  void HandleDiagnostic(DiagnosticsEngine::Level DiagLevel,
                        const Diagnostic &Info) override;

  // Flushes the internal diagnostics buffer to the ClangTidyContext.
  void finish() override;

private:
  void addFixes(const Diagnostic &Info, ClangTidyError &Error);
  ClangTidyMessage getMessage(const Diagnostic &Info) const;
  void finalizeLastError();

  ClangTidyContext &Context;
  OwningPtr<DiagnosticsEngine> Diags;
  SmallVector<ClangTidyError, 8> Errors;
  bool LastErrorRelatesToUserCode;
};

} // end namespace tidy
} // end namespace clang

#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_CLANG_TIDY_DIAGNOSTIC_CONSUMER_H