ClangTidyDiagnosticConsumer.cpp

/// Adds the Diagnostic name to the Original name using ', ' as a seperator, but
/// makes sure the diagnostic names are sorted alphabetically
static std::string appendDuplicatedDiagName(StringRef Name,
                                            StringRef AppendName) {
  constexpr StringRef Delimiter = ", ";
  SmallVector<StringRef, 2> Split;
  Name.split(Split, Delimiter, -1, false);
  Split.push_back(AppendName);
  llvm::sort(Split);
  return llvm::join(Split, Delimiter);
}

void ClangTidyDiagnosticConsumer::removeDuplicatedFixesOfAliasCheckers() {
  using UniqueErrorSet =
      std::set<ClangTidyError *, LessClangTidyErrorWithoutDiagnosticName>;
  llvm::SmallSet<ClangTidyError *, 8> RemoveErrors;
  UniqueErrorSet UniqueErrors;
  for (auto &Error : Errors) {
    std::pair<UniqueErrorSet::iterator, bool> Inserted =
        UniqueErrors.insert(&Error);
    // If we already have an error like this, just with the different
    // DiagnosticName, remove its Fix since we don't need same fix twice
    if (!Inserted.second) {
      ClangTidyError *FirstError = *Inserted.first;
      if (Error.Message.Fix == FirstError->Message.Fix) {
        // Flag to remove the second error from diagnostics and join the diag
        // names.
        RemoveErrors.insert(&Error);
        FirstError->DiagnosticName = appendDuplicatedDiagName(
            FirstError->DiagnosticName, Error.DiagnosticName);
      } else {
        // Same Error message, but conflicting fix its. Ignore this case,
        // clang-tidy will detect the conflict and issue warnings.
      }
    }
  }
  if (!RemoveErrors.empty()) {
    Errors.erase(std::remove_if(Errors.begin(), Errors.end(),
                                [&](ClangTidyError &Error) {
                                  return RemoveErrors.count(&Error) > 0;
                                }),
                 Errors.end());
  }
}